diff --git a/core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java b/core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
index 14f058a75d0..4dd267984bf 100644
--- a/core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
+++ b/core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
@@ -72,6 +72,7 @@ public enum BuiltinFunctionName {
   ARRAY_LENGTH(FunctionName.of("array_length")),
   ARRAY_SLICE(FunctionName.of("array_slice"), true),
   ARRAY_COMPACT(FunctionName.of("array_compact")),
+  ARRAY_TO_CSV(FunctionName.of("array_to_csv")),
   MAP_APPEND(FunctionName.of("map_append"), true),
   MAP_CONCAT(FunctionName.of("map_concat"), true),
   MAP_REMOVE(FunctionName.of("map_remove"), true),
diff --git a/core/src/main/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImpl.java b/core/src/main/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImpl.java
new file mode 100644
index 00000000000..8dc0855f34a
--- /dev/null
+++ b/core/src/main/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImpl.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.expression.function.CollectionUDF;
+
+import java.util.List;
+import org.apache.calcite.adapter.enumerable.NotNullImplementor;
+import org.apache.calcite.adapter.enumerable.NullPolicy;
+import org.apache.calcite.adapter.enumerable.RexToLixTranslator;
+import org.apache.calcite.linq4j.tree.Expression;
+import org.apache.calcite.linq4j.tree.Expressions;
+import org.apache.calcite.linq4j.tree.Types;
+import org.apache.calcite.rel.type.RelDataTypeFactory;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.sql.type.CompositeOperandTypeChecker;
+import org.apache.calcite.sql.type.OperandTypes;
+import org.apache.calcite.sql.type.SqlReturnTypeInference;
+import org.apache.calcite.sql.type.SqlTypeFamily;
+import org.apache.calcite.sql.type.SqlTypeName;
+import org.opensearch.sql.expression.function.ImplementorUDF;
+import org.opensearch.sql.expression.function.UDFOperandMetadata;
+
+/** ARRAY_TO_CSV function implementation that converts an array to a CSV string. */
+public class ArrayToCsvFunctionImpl extends ImplementorUDF {
+
+  public ArrayToCsvFunctionImpl() {
+    super(new ArrayToCsvImplementor(), NullPolicy.ARG0);
+  }
+
+  @Override
+  public SqlReturnTypeInference getReturnTypeInference() {
+    return sqlOperatorBinding -> {
+      RelDataTypeFactory typeFactory = sqlOperatorBinding.getTypeFactory();
+      return typeFactory.createTypeWithNullability(
+          typeFactory.createSqlType(SqlTypeName.VARCHAR), true);
+    };
+  }
+
+  @Override
+  public UDFOperandMetadata getOperandMetadata() {
+    // Accept ARRAY as first argument, optional STRING as second argument (delimiter)
+    return UDFOperandMetadata.wrap(
+        (CompositeOperandTypeChecker)
+            OperandTypes.family(SqlTypeFamily.ARRAY)
+                .or(OperandTypes.family(SqlTypeFamily.ARRAY, SqlTypeFamily.CHARACTER)));
+  }
+
+  public static class ArrayToCsvImplementor implements NotNullImplementor {
+    @Override
+    public Expression implement(
+        RexToLixTranslator translator, RexCall call, List<Expression> translatedOperands) {
+      // Handle both 1-argument (with default delimiter) and 2-argument cases
+      if (translatedOperands.size() == 1) {
+        // ARRAY_TO_CSV(array) - use default delimiter ","
+        return Expressions.call(
+            Types.lookupMethod(
+                ArrayToCsvFunctionImpl.class, "arrayToCsv", List.class, String.class),
+            translatedOperands.get(0),
+            Expressions.constant(","));
+      } else if (translatedOperands.size() == 2) {
+        // ARRAY_TO_CSV(array, delimiter)
+        return Expressions.call(
+            Types.lookupMethod(
+                ArrayToCsvFunctionImpl.class, "arrayToCsv", List.class, String.class),
+            translatedOperands.get(0),
+            translatedOperands.get(1));
+      } else {
+        throw new IllegalArgumentException(
+            "ARRAY_TO_CSV expects 1 or 2 arguments, got " + translatedOperands.size());
+      }
+    }
+  }
+
+  /**
+   * Converts an array to a CSV string.
+   *
+   * @param array The array to convert
+   * @param delimiter The delimiter to use for joining values
+   * @return CSV string representation of the array
+   */
+  public static String arrayToCsv(List<Object> array, String delimiter) {
+    if (array == null) {
+      return null;
+    }
+
+    if (delimiter == null) {
+      delimiter = ",";
+    }
+
+    if (array.isEmpty()) {
+      return "";
+    }
+
+    StringBuilder result = new StringBuilder();
+    for (int i = 0; i < array.size(); i++) {
+      if (i > 0) {
+        result.append(delimiter);
+      }
+      Object element = array.get(i);
+      if (element != null) {
+        result.append(element.toString());
+      }
+    }
+
+    return result.toString();
+  }
+}
diff --git a/core/src/main/java/org/opensearch/sql/expression/function/PPLBuiltinOperators.java b/core/src/main/java/org/opensearch/sql/expression/function/PPLBuiltinOperators.java
index 0a5b0fe0e03..8bbca5199f1 100644
--- a/core/src/main/java/org/opensearch/sql/expression/function/PPLBuiltinOperators.java
+++ b/core/src/main/java/org/opensearch/sql/expression/function/PPLBuiltinOperators.java
@@ -43,6 +43,7 @@
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.expression.datetime.DateTimeFunctions;
 import org.opensearch.sql.expression.function.CollectionUDF.ArrayFunctionImpl;
+import org.opensearch.sql.expression.function.CollectionUDF.ArrayToCsvFunctionImpl;
 import org.opensearch.sql.expression.function.CollectionUDF.ExistsFunctionImpl;
 import org.opensearch.sql.expression.function.CollectionUDF.FilterFunctionImpl;
 import org.opensearch.sql.expression.function.CollectionUDF.ForallFunctionImpl;
@@ -400,6 +401,7 @@ public class PPLBuiltinOperators extends ReflectiveSqlOperatorTable {
   public static final SqlOperator FORALL = new ForallFunctionImpl().toUDF("forall");
   public static final SqlOperator EXISTS = new ExistsFunctionImpl().toUDF("exists");
   public static final SqlOperator ARRAY = new ArrayFunctionImpl().toUDF("array");
+  public static final SqlOperator ARRAY_TO_CSV = new ArrayToCsvFunctionImpl().toUDF("array_to_csv");
   public static final SqlOperator MAP_APPEND = new MapAppendFunctionImpl().toUDF("map_append");
   public static final SqlOperator MAP_REMOVE = new MapRemoveFunctionImpl().toUDF("MAP_REMOVE");
   public static final SqlOperator MVAPPEND = new MVAppendFunctionImpl().toUDF("mvappend");
diff --git a/core/src/main/java/org/opensearch/sql/expression/function/PPLFuncImpTable.java b/core/src/main/java/org/opensearch/sql/expression/function/PPLFuncImpTable.java
index 849c60fe4eb..2ecb5c486ed 100644
--- a/core/src/main/java/org/opensearch/sql/expression/function/PPLFuncImpTable.java
+++ b/core/src/main/java/org/opensearch/sql/expression/function/PPLFuncImpTable.java
@@ -19,6 +19,7 @@
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ARRAY_COMPACT;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ARRAY_LENGTH;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ARRAY_SLICE;
+import static org.opensearch.sql.expression.function.BuiltinFunctionName.ARRAY_TO_CSV;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ASCII;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ASIN;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ATAN;
@@ -1062,6 +1063,7 @@ void populate() {
       registerOperator(ARRAY_LENGTH, SqlLibraryOperators.ARRAY_LENGTH);
       registerOperator(ARRAY_SLICE, SqlLibraryOperators.ARRAY_SLICE);
       registerOperator(ARRAY_COMPACT, SqlLibraryOperators.ARRAY_COMPACT);
+      registerOperator(ARRAY_TO_CSV, PPLBuiltinOperators.ARRAY_TO_CSV);
       registerOperator(FORALL, PPLBuiltinOperators.FORALL);
       registerOperator(EXISTS, PPLBuiltinOperators.EXISTS);
       registerOperator(FILTER, PPLBuiltinOperators.FILTER);
diff --git a/core/src/test/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImplTest.java b/core/src/test/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImplTest.java
new file mode 100644
index 00000000000..be91a84a498
--- /dev/null
+++ b/core/src/test/java/org/opensearch/sql/expression/function/CollectionUDF/ArrayToCsvFunctionImplTest.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.expression.function.CollectionUDF;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class ArrayToCsvFunctionImplTest {
+
+  @Test
+  void testArrayToCsvWithDefaultDelimiter() {
+    List<Object> array = Arrays.asList("GET", "READ", "WRITE");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("GET,READ,WRITE", result);
+  }
+
+  @Test
+  void testArrayToCsvWithCustomDelimiter() {
+    List<Object> array = Arrays.asList("GET", "READ", "WRITE");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ", ");
+    assertEquals("GET, READ, WRITE", result);
+  }
+
+  @Test
+  void testArrayToCsvWithPipeDelimiter() {
+    List<Object> array = Arrays.asList("GET", "READ", "WRITE");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, " | ");
+    assertEquals("GET | READ | WRITE", result);
+  }
+
+  @Test
+  void testArrayToCsvWithEmptyArray() {
+    List<Object> array = Collections.emptyList();
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullArray() {
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(null, ",");
+    assertNull(result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullElements() {
+    List<Object> array = Arrays.asList("GET", null, "WRITE");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("GET,,WRITE", result);
+  }
+
+  @Test
+  void testArrayToCsvWithSingleElement() {
+    List<Object> array = Arrays.asList("GET");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("GET", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNumbers() {
+    List<Object> array = Arrays.asList(1, 2, 3);
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("1,2,3", result);
+  }
+
+  @Test
+  void testArrayToCsvWithMixedTypes() {
+    List<Object> array = Arrays.asList("GET", 123, true);
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("GET,123,true", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullDelimiter() {
+    List<Object> array = Arrays.asList("a", "b", "c");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, null);
+    assertEquals("a,b,c", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullDelimiterAndSingleElement() {
+    List<Object> array = Arrays.asList("GET");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, null);
+    assertEquals("GET", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullDelimiterAndEmptyArray() {
+    List<Object> array = Collections.emptyList();
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, null);
+    assertEquals("", result);
+  }
+
+  @Test
+  void testArrayToCsvWithMultipleNullElements() {
+    List<Object> array = Arrays.asList("a", null, null, "b");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("a,,,b", result);
+  }
+
+  @Test
+  void testArrayToCsvWithLeadingNullElement() {
+    List<Object> array = Arrays.asList(null, "a", "b");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals(",a,b", result);
+  }
+
+  @Test
+  void testArrayToCsvWithTrailingNullElement() {
+    List<Object> array = Arrays.asList("a", "b", null);
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals("a,b,", result);
+  }
+
+  @Test
+  void testArrayToCsvWithAllNullElements() {
+    List<Object> array = Arrays.asList(null, null, null);
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, ",");
+    assertEquals(",,", result);
+  }
+
+  @Test
+  void testArrayToCsvWithNullElementsAndCustomDelimiter() {
+    List<Object> array = Arrays.asList("GET", null, "WRITE");
+    String result = ArrayToCsvFunctionImpl.arrayToCsv(array, " | ");
+    assertEquals("GET |  | WRITE", result);
+  }
+}
diff --git a/docs/user/ppl/functions/array_to_csv.md b/docs/user/ppl/functions/array_to_csv.md
new file mode 100644
index 00000000000..8d8e552504d
--- /dev/null
+++ b/docs/user/ppl/functions/array_to_csv.md
@@ -0,0 +1,202 @@
+# ARRAY_TO_CSV
+
+**Usage**: `array_to_csv(array, [delimiter])`
+
+Converts an array to a comma-separated values (CSV) string representation. All array elements are converted to their string representation and joined using the specified delimiter.
+
+**Parameters**:
+
+- `array` (Required): An array expression of any supported data type to convert to CSV.
+- `delimiter` (Optional): The string to use as a separator between array elements. Defaults to comma (",").
+
+**Return type**: `STRING`
+
+## Example
+
+The following example converts an array to CSV with the default comma delimiter:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('apple', 'banana', 'cherry'))
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++-------------------------+
+| result                  |
+|-------------------------|
+| apple,banana,cherry     |
++-------------------------+
+```
+
+The following example uses a custom delimiter:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('a', 'b', 'c'), '|')
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++---------+
+| result  |
+|---------|
+| a|b|c   |
++---------+
+```
+
+The following example converts a numeric array:
+
+```ppl
+source=people
+| eval result = array_to_csv(array(1, 2, 3, 4))
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++---------+
+| result  |
+|---------|
+| 1,2,3,4 |
++---------+
+```
+
+The following example handles mixed data types:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('text', 123, 45.67), ';')
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++----------------+
+| result         |
+|----------------|
+| text;123;45.67 |
++----------------+
+```
+
+The following example uses multi-character delimiters:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('apple', 'banana', 'cherry'), ' -> ')
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++---------------------------+
+| result                    |
+|---------------------------|
+| apple -> banana -> cherry |
++---------------------------+
+```
+
+The following example uses arrays created from real database fields:
+
+```ppl
+source=accounts
+| eval names_array = array(firstname, lastname)
+| eval full_name = array_to_csv(names_array, ' ')
+| fields firstname, lastname, full_name
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++------------+-----------+--------------+
+| firstname  | lastname  | full_name    |
+|------------|-----------|--------------|
+| Amber      | Duke      | Amber Duke   |
++------------+-----------+--------------+
+```
+
+The following example shows behavior with empty arrays:
+
+```ppl
+source=people
+| eval result = array_to_csv(array())
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++--------+
+| result |
+|--------|
+|        |
++--------+
+```
+
+The following example shows behavior with single element arrays:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('single'))
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++--------+
+| result |
+|--------|
+| single |
++--------+
+```
+
+The following example demonstrates null element handling:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('a', null, 'c'))
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++--------+
+| result |
+|--------|
+| a,,c   |
++--------+
+```
+
+## Limitations
+
+- The function converts all array elements to their string representation
+- Null array elements are represented as empty strings in the output
+- If the input array is null, the function returns null
+- If the delimiter is null, it defaults to comma (",")
\ No newline at end of file
diff --git a/docs/user/ppl/functions/collection.md b/docs/user/ppl/functions/collection.md
index 006a49ef6d5..a434a2607af 100644
--- a/docs/user/ppl/functions/collection.md
+++ b/docs/user/ppl/functions/collection.md
@@ -91,6 +91,81 @@ fetched rows / total rows = 1/1
 | 3      |
 +--------+
 ```
+
+## ARRAY_TO_CSV
+
+**Usage**: `array_to_csv(array, [delimiter])`
+
+Converts an array to a comma-separated values (CSV) string representation. All array elements are converted to their string representation and joined using the specified delimiter.
+
+**Parameters**:
+
+- `array` (Required): An array expression of any supported data type to convert to CSV.
+- `delimiter` (Optional): The string to use as a separator between array elements. Defaults to comma (",").
+
+**Return type**: `STRING`
+
+#### Example
+
+The following example converts an array to CSV with the default comma delimiter:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('apple', 'banana', 'cherry'))
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++-------------------------+
+| result                  |
+|-------------------------|
+| apple,banana,cherry     |
++-------------------------+
+```
+
+The following example uses a custom delimiter:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('a', 'b', 'c'), '|')
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++---------+
+| result  |
+|---------|
+| a|b|c   |
++---------+
+```
+
+The following example handles mixed data types:
+
+```ppl
+source=people
+| eval result = array_to_csv(array('text', 123, 45.67), ';')
+| fields result
+| head 1
+```
+
+The query returns the following results:
+
+```text
+fetched rows / total rows = 1/1
++----------------+
+| result         |
+|----------------|
+| text;123;45.67 |
++----------------+
+```
   
 ## FORALL
 
diff --git a/integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteArrayFunctionIT.java b/integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteArrayFunctionIT.java
index 26e8ecf73f6..afc4b579328 100644
--- a/integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteArrayFunctionIT.java
+++ b/integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteArrayFunctionIT.java
@@ -867,4 +867,118 @@ public void testMvmapWithEvalFieldReference() throws IOException {
     verifySchema(actual, schema("result", "array"));
     verifyDataRows(actual, rows(List.of(10, 20, 30)));
   }
+
+  @Test
+  public void testArrayToCsvBasic() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array('apple', 'banana', 'cherry'), result ="
+                    + " array_to_csv(arr) | head 1 | fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("apple,banana,cherry"));
+  }
+
+  @Test
+  public void testArrayToCsvWithCustomDelimiter() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array('apple', 'banana', 'cherry'), result ="
+                    + " array_to_csv(arr, '|') | head 1 | fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("apple|banana|cherry"));
+  }
+
+  @Test
+  public void testArrayToCsvWithNumbers() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array(1, 2, 3, 4), result = array_to_csv(arr) | head 1 |"
+                    + " fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("1,2,3,4"));
+  }
+
+  @Test
+  public void testArrayToCsvWithMixedTypes() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array('text', 123, 45.67), result = array_to_csv(arr, ';')"
+                    + " | head 1 | fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("text;123;45.67"));
+  }
+
+  @Test
+  public void testArrayToCsvWithEmptyArray() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array(), result = array_to_csv(arr) | head 1 | fields"
+                    + " result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows(""));
+  }
+
+  @Test
+  public void testArrayToCsvWithSingleElement() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array('single'), result = array_to_csv(arr) | head 1 |"
+                    + " fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("single"));
+  }
+
+  @Test
+  public void testArrayToCsvWithSpecialDelimiters() throws IOException {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval arr = array('a', 'b', 'c'), result = array_to_csv(arr, ' -> ') |"
+                    + " head 1 | fields result",
+                TEST_INDEX_BANK));
+
+    verifySchema(actual, schema("result", "string"));
+    verifyDataRows(actual, rows("a -> b -> c"));
+  }
+
+  @Test
+  public void testArrayToCsvWithRealFields() throws IOException {
+    // Test array_to_csv with arrays created from real fields
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | eval names_array = array(firstname, lastname), result ="
+                    + " array_to_csv(names_array, ' ') | fields firstname, lastname, result | head"
+                    + " 1",
+                TEST_INDEX_BANK));
+
+    verifySchema(
+        actual,
+        schema("firstname", "string"),
+        schema("lastname", "string"),
+        schema("result", "string"));
+    // Verify that array_to_csv correctly joins the firstname and lastname fields
+    JSONArray dataRows = actual.getJSONArray("datarows");
+    assertTrue(dataRows.length() > 0);
+    JSONArray firstRow = dataRows.getJSONArray(0);
+    assertEquals(firstRow.getString(0) + " " + firstRow.getString(1), firstRow.getString(2));
+  }
 }
diff --git a/ppl/src/main/antlr/OpenSearchPPLLexer.g4 b/ppl/src/main/antlr/OpenSearchPPLLexer.g4
index 4bc69a8f295..b42729e869f 100644
--- a/ppl/src/main/antlr/OpenSearchPPLLexer.g4
+++ b/ppl/src/main/antlr/OpenSearchPPLLexer.g4
@@ -480,6 +480,7 @@ ISBLANK:                            'ISBLANK';
 // COLLECTION FUNCTIONS
 ARRAY:                              'ARRAY';
 ARRAY_LENGTH:                       'ARRAY_LENGTH';
+ARRAY_TO_CSV:                       'ARRAY_TO_CSV';
 MVAPPEND:                           'MVAPPEND';
 MVJOIN:                             'MVJOIN';
 MVINDEX:                            'MVINDEX';
diff --git a/ppl/src/main/antlr/OpenSearchPPLParser.g4 b/ppl/src/main/antlr/OpenSearchPPLParser.g4
index bcaaa105774..628105d6d54 100644
--- a/ppl/src/main/antlr/OpenSearchPPLParser.g4
+++ b/ppl/src/main/antlr/OpenSearchPPLParser.g4
@@ -1231,6 +1231,7 @@ geoipFunctionName
 collectionFunctionName
     : ARRAY
     | ARRAY_LENGTH
+    | ARRAY_TO_CSV
     | MVAPPEND
     | MVJOIN
     | MVINDEX