diff --git a/lib/workos/organizations.ex b/lib/workos/organizations.ex
index 3334d249..d3b3ba13 100644
--- a/lib/workos/organizations.ex
+++ b/lib/workos/organizations.ex
@@ -75,6 +75,20 @@ defmodule WorkOS.Organizations do
     )
   end
 
+  @doc """
+  Gets an organization by external ID.
+  """
+  @spec get_organization_by_external_id(String.t()) :: WorkOS.Client.response(Organization.t())
+  @spec get_organization_by_external_id(WorkOS.Client.t(), String.t()) ::
+          WorkOS.Client.response(Organization.t())
+  def get_organization_by_external_id(client \\ WorkOS.client(), external_id) do
+    WorkOS.Client.get(client, Organization, "/organizations/external_id/:external_id",
+      opts: [
+        path_params: [external_id: external_id]
+      ]
+    )
+  end
+
   @doc """
   Creates an organization.
 
diff --git a/lib/workos/organizations/organization.ex b/lib/workos/organizations/organization.ex
index 17473925..07711f09 100644
--- a/lib/workos/organizations/organization.ex
+++ b/lib/workos/organizations/organization.ex
@@ -13,6 +13,7 @@ defmodule WorkOS.Organizations.Organization do
           object: String.t(),
           name: String.t(),
           allow_profiles_outside_organization: boolean(),
+          external_id: String.t() | nil,
           domains: list(Domain.t()) | nil,
           updated_at: String.t(),
           created_at: String.t()
@@ -32,6 +33,7 @@ defmodule WorkOS.Organizations.Organization do
     :object,
     :name,
     :allow_profiles_outside_organization,
+    :external_id,
     :domains,
     :updated_at,
     :created_at
@@ -45,6 +47,7 @@ defmodule WorkOS.Organizations.Organization do
       name: map["name"],
       domains: Castable.cast_list(Domain, map["domains"]),
       allow_profiles_outside_organization: map["allow_profiles_outside_organization"],
+      external_id: map["external_id"],
       updated_at: map["updated_at"],
       created_at: map["created_at"]
     }
diff --git a/lib/workos/user_management.ex b/lib/workos/user_management.ex
index c96aa2ea..941aa842 100644
--- a/lib/workos/user_management.ex
+++ b/lib/workos/user_management.ex
@@ -85,6 +85,19 @@ defmodule WorkOS.UserManagement do
     )
   end
 
+  @doc """
+  Gets a user by external ID.
+  """
+  @spec get_user_by_external_id(String.t()) :: WorkOS.Client.response(User.t())
+  @spec get_user_by_external_id(WorkOS.Client.t(), String.t()) :: WorkOS.Client.response(User.t())
+  def get_user_by_external_id(client \\ WorkOS.client(), external_id) do
+    WorkOS.Client.get(client, User, "/user_management/users/external_id/:external_id",
+      opts: [
+        path_params: [external_id: external_id]
+      ]
+    )
+  end
+
   @doc """
   Lists all users.
 
diff --git a/lib/workos/user_management/user.ex b/lib/workos/user_management/user.ex
index ece7d3e0..8476e2e5 100644
--- a/lib/workos/user_management/user.ex
+++ b/lib/workos/user_management/user.ex
@@ -11,6 +11,7 @@ defmodule WorkOS.UserManagement.User do
           email_verified: boolean(),
           first_name: String.t() | nil,
           last_name: String.t() | nil,
+          external_id: String.t() | nil,
           updated_at: String.t(),
           created_at: String.t()
         }
@@ -28,6 +29,7 @@ defmodule WorkOS.UserManagement.User do
     :email_verified,
     :first_name,
     :last_name,
+    :external_id,
     :updated_at,
     :created_at
   ]
@@ -40,6 +42,7 @@ defmodule WorkOS.UserManagement.User do
       email_verified: map["email_verified"],
       first_name: map["first_name"],
       last_name: map["last_name"],
+      external_id: map["external_id"],
       updated_at: map["updated_at"],
       created_at: map["created_at"]
     }
diff --git a/test/support/organizations_client_mock.ex b/test/support/organizations_client_mock.ex
index 71a5cc12..3ebf7a7e 100644
--- a/test/support/organizations_client_mock.ex
+++ b/test/support/organizations_client_mock.ex
@@ -105,6 +105,39 @@ defmodule WorkOS.Organizations.ClientMock do
     end)
   end
 
+  def get_organization_by_external_id(context, opts \\ []) do
+    Tesla.Mock.mock(fn request ->
+      %{api_key: api_key} = context
+
+      external_id = opts |> Keyword.get(:assert_fields) |> Keyword.get(:external_id)
+      assert request.method == :get
+      assert request.url == "#{WorkOS.base_url()}/organizations/external_id/#{external_id}"
+
+      assert Enum.find(request.headers, &(elem(&1, 0) == "Authorization")) ==
+               {"Authorization", "Bearer #{api_key}"}
+
+      success_body = %{
+        "id" => "org_01EHT88Z8J8795GZNQ4ZP1J81T",
+        "object" => "organization",
+        "name" => "Test Organization",
+        "allow_profiles_outside_organization" => false,
+        "external_id" => external_id,
+        "domains" => [
+          %{
+            "domain" => "example.com",
+            "object" => "organization_domain",
+            "id" => "org_domain_01EHT88Z8WZEFWYPM6EC9BX2R8"
+          }
+        ],
+        "created_at" => "2023-07-17T20:07:20.055Z",
+        "updated_at" => "2023-07-17T20:07:20.055Z"
+      }
+
+      {status, body} = Keyword.get(opts, :respond_with, {200, success_body})
+      %Tesla.Env{status: status, body: body}
+    end)
+  end
+
   def create_organization(context, opts \\ []) do
     Tesla.Mock.mock(fn request ->
       %{api_key: api_key} = context
diff --git a/test/support/user_management_client_mock.ex b/test/support/user_management_client_mock.ex
index bdd7dece..ce328e29 100644
--- a/test/support/user_management_client_mock.ex
+++ b/test/support/user_management_client_mock.ex
@@ -11,7 +11,8 @@ defmodule WorkOS.UserManagement.ClientMock do
     "last_name" => "User",
     "created_at" => "2023-07-18T02:07:19.911Z",
     "updated_at" => "2023-07-18T02:07:19.911Z",
-    "email_verified" => true
+    "email_verified" => true,
+    "external_id" => "ext_user_123"
   }
 
   @invitation_mock %{
@@ -90,6 +91,26 @@ defmodule WorkOS.UserManagement.ClientMock do
     end)
   end
 
+  def get_user_by_external_id(context, opts \\ []) do
+    Tesla.Mock.mock(fn request ->
+      %{api_key: api_key} = context
+
+      external_id = opts |> Keyword.get(:assert_fields) |> Keyword.get(:external_id)
+      assert request.method == :get
+
+      assert request.url ==
+               "#{WorkOS.base_url()}/user_management/users/external_id/#{external_id}"
+
+      assert Enum.find(request.headers, &(elem(&1, 0) == "Authorization")) ==
+               {"Authorization", "Bearer #{api_key}"}
+
+      success_body = @user_mock
+
+      {status, body} = Keyword.get(opts, :respond_with, {200, success_body})
+      %Tesla.Env{status: status, body: body}
+    end)
+  end
+
   def list_users(context, opts \\ []) do
     Tesla.Mock.mock(fn request ->
       %{api_key: api_key} = context
diff --git a/test/workos/organizations_test.exs b/test/workos/organizations_test.exs
index 56648226..a51efb9d 100644
--- a/test/workos/organizations_test.exs
+++ b/test/workos/organizations_test.exs
@@ -55,6 +55,22 @@ defmodule WorkOS.OrganizationsTest do
     end
   end
 
+  describe "get_organization_by_external_id" do
+    test "requests an organization by external_id", context do
+      opts = [external_id: "ext_org_123"]
+      context |> ClientMock.get_organization_by_external_id(assert_fields: opts)
+
+      assert {:ok, %WorkOS.Organizations.Organization{id: id, external_id: external_id}} =
+               WorkOS.Organizations.get_organization_by_external_id(
+                 opts
+                 |> Keyword.get(:external_id)
+               )
+
+      refute is_nil(id)
+      assert external_id == "ext_org_123"
+    end
+  end
+
   describe "create_organization" do
     test "with an idempotency key, includes an idempotency key with request", context do
       opts = [
diff --git a/test/workos/user_management_test.exs b/test/workos/user_management_test.exs
index 1b778405..ae120763 100644
--- a/test/workos/user_management_test.exs
+++ b/test/workos/user_management_test.exs
@@ -136,6 +136,19 @@ defmodule WorkOS.UserManagementTest do
     end
   end
 
+  describe "get_user_by_external_id" do
+    test "requests a user by external_id", context do
+      opts = [external_id: "ext_user_123"]
+      context |> ClientMock.get_user_by_external_id(assert_fields: opts)
+
+      assert {:ok, %WorkOS.UserManagement.User{id: id, external_id: external_id}} =
+               WorkOS.UserManagement.get_user_by_external_id(opts |> Keyword.get(:external_id))
+
+      refute is_nil(id)
+      assert external_id == "ext_user_123"
+    end
+  end
+
   describe "list_users" do
     test "without any options, returns users and metadata", context do
       context