diff --git a/frontend/common/types/responses.ts b/frontend/common/types/responses.ts
index b3edece5bd24..ef606bdb1875 100644
--- a/frontend/common/types/responses.ts
+++ b/frontend/common/types/responses.ts
@@ -160,6 +160,11 @@ export type SegmentRule = {
   conditions: SegmentCondition[]
   version_of: number | undefined
 }
+export type SegmentMembership = {
+  environment: number
+  count: number
+  last_synced_at: string
+}
 export type Segment = {
   id: number
   rules: SegmentRule[]
@@ -169,6 +174,7 @@ export type Segment = {
   project: string | number
   feature?: number
   metadata: Metadata[] | []
+  memberships?: SegmentMembership[]
 }
 export type ProjectChangeRequest = Omit<
   ChangeRequest,
diff --git a/frontend/web/components/EnvironmentSelect.tsx b/frontend/web/components/EnvironmentSelect.tsx
index 966129dabe0a..8636953ed48c 100644
--- a/frontend/web/components/EnvironmentSelect.tsx
+++ b/frontend/web/components/EnvironmentSelect.tsx
@@ -3,6 +3,12 @@ import { useGetEnvironmentsQuery } from 'common/services/useEnvironment'
 import { Props } from 'react-select'
 import { Environment } from 'common/types/responses'
 
+export type EnvironmentSelectOption = {
+  value: string
+  label: string
+  environment: Environment | null
+}
+
 type EnvironmentSelectType = Partial<Omit<Props, 'value'>> & {
   projectId: number
   value?: string
@@ -73,11 +79,9 @@ const EnvironmentSelect: FC<EnvironmentSelectType> = ({
           ? [{ environment: null, label: 'All Environments', value: '' }]
           : []
         ).concat(environments)}
-        onChange={(value: {
-          value: string
-          label: string
-          environment: Environment
-        }) => onChange(value?.value || '', value?.environment)}
+        onChange={(value: EnvironmentSelectOption) =>
+          onChange(value?.value || '', value?.environment)
+        }
       />
     </div>
   )
diff --git a/frontend/web/components/Tooltip.tsx b/frontend/web/components/Tooltip.tsx
index 7057d37110ea..c0be5e78b7f5 100644
--- a/frontend/web/components/Tooltip.tsx
+++ b/frontend/web/components/Tooltip.tsx
@@ -14,11 +14,13 @@ export type TooltipProps = {
   effect?: 'float' | 'solid'
   afterShow?: () => void
   renderInPortal?: boolean
+  delayShow?: number
 }
 
 const Tooltip: FC<TooltipProps> = ({
   afterShow,
   children,
+  delayShow = 500,
   effect,
   place,
   plainText,
@@ -53,7 +55,7 @@ const Tooltip: FC<TooltipProps> = ({
         place={place || 'top'}
         float={effect === 'float'}
         afterShow={afterShow}
-        delayShow={500}
+        delayShow={delayShow}
         style={{ wordBreak: 'break-word' }}
       />
     </>
diff --git a/frontend/web/components/modals/CreateSegment.tsx b/frontend/web/components/modals/CreateSegment.tsx
index a4e4510a4698..db77d1063ac2 100644
--- a/frontend/web/components/modals/CreateSegment.tsx
+++ b/frontend/web/components/modals/CreateSegment.tsx
@@ -28,6 +28,7 @@ import {
 } from 'common/services/useSegment'
 import Utils from 'common/utils/utils'
 import AssociatedSegmentOverrides from 'components/segments/AssociatedSegmentOverrides'
+import { SegmentMembershipTotalBadge } from 'components/segments/SegmentMembershipBadge'
 import Button from 'components/base/forms/Button'
 import InfoMessage from 'components/InfoMessage'
 import InputGroup from 'components/base/forms/InputGroup'
@@ -582,7 +583,17 @@ const CreateSegment: FC<CreateSegmentType> = ({
               />
             </div>
           </TabItem>
-          <TabItem tabLabel='Identities'>
+          <TabItem
+            tabLabelString='Identities'
+            tabLabel={
+              <>
+                Identities
+                <SegmentMembershipTotalBadge
+                  memberships={segment.memberships}
+                />
+              </>
+            }
+          >
             <div className='my-4'>
               <CreateSegmentUsersTabContent
                 projectId={projectId}
@@ -595,6 +606,7 @@ const CreateSegment: FC<CreateSegmentType> = ({
                 name={name}
                 searchInput={searchInput}
                 setSearchInput={setSearchInput}
+                memberships={segment.memberships}
               />
             </div>
           </TabItem>
diff --git a/frontend/web/components/modals/CreateSegmentUsersTabContent.tsx b/frontend/web/components/modals/CreateSegmentUsersTabContent.tsx
index 69b8c0e87248..8025cd85caef 100644
--- a/frontend/web/components/modals/CreateSegmentUsersTabContent.tsx
+++ b/frontend/web/components/modals/CreateSegmentUsersTabContent.tsx
@@ -1,16 +1,21 @@
 import React, { FC } from 'react'
-import EnvironmentSelect from 'components/EnvironmentSelect'
+import moment from 'moment'
+import EnvironmentSelect, {
+  EnvironmentSelectOption,
+} from 'components/EnvironmentSelect'
 import PanelSearch from 'components/PanelSearch'
 import InfoMessage from 'components/InfoMessage'
 import InputGroup from 'components/base/forms/InputGroup'
 import Utils from 'common/utils/utils'
-import { Res } from 'common/types/responses'
+import { Environment, Res, SegmentMembership } from 'common/types/responses'
 import Icon from 'components/icons/Icon'
 import {
   identitySegmentService,
   useGetIdentitySegmentsQuery,
 } from 'common/services/useIdentitySegment'
 import { getStore } from 'common/store'
+import ProjectStore from 'common/stores/project-store'
+import { SegmentMembershipEnvBadge } from 'components/segments/SegmentMembershipBadge'
 
 interface CreateSegmentUsersTabContentProps {
   projectId: string | number
@@ -23,6 +28,7 @@ interface CreateSegmentUsersTabContentProps {
   name: string
   searchInput: string
   setSearchInput: (input: string) => void
+  memberships?: SegmentMembership[]
 }
 
 type UserRowType = {
@@ -80,6 +86,7 @@ const CreateSegmentUsersTabContent: React.FC<
   environmentId,
   identities,
   identitiesLoading,
+  memberships,
   name,
   page,
   projectId,
@@ -88,6 +95,36 @@ const CreateSegmentUsersTabContent: React.FC<
   setPage,
   setSearchInput,
 }) => {
+  const membershipByEnvId = React.useMemo(() => {
+    const map = new Map<number, SegmentMembership>()
+    ;(memberships ?? []).forEach((m) => map.set(m.environment, m))
+    return map
+  }, [memberships])
+
+  const renderEnvOption = ({ environment, label }: EnvironmentSelectOption) => {
+    const membership = environment
+      ? membershipByEnvId.get(environment.id)
+      : undefined
+    return (
+      <span className='d-flex align-items-center'>
+        <span>{label}</span>
+        {environment && membership && (
+          <SegmentMembershipEnvBadge
+            membership={membership}
+            environment={environment}
+          />
+        )}
+      </span>
+    )
+  }
+
+  const selectedMembership = React.useMemo(() => {
+    if (!environmentId) return null
+    const envs = (ProjectStore.getEnvs() as Environment[] | null) || []
+    const env = envs.find((e) => e.api_key === environmentId)
+    return env ? membershipByEnvId.get(env.id) ?? null : null
+  }, [environmentId, membershipByEnvId])
+
   return (
     <>
       <InfoMessage collapseId={'random-identity-sample'}>
@@ -100,13 +137,24 @@ const CreateSegmentUsersTabContent: React.FC<
             title='Environment'
             className='col-4'
             component={
-              <EnvironmentSelect
-                projectId={`${projectId}`}
-                value={environmentId}
-                onChange={(environmentId: string) => {
-                  setEnvironmentId(environmentId)
-                }}
-              />
+              <>
+                <EnvironmentSelect
+                  projectId={`${projectId}`}
+                  value={environmentId}
+                  onChange={(environmentId: string) => {
+                    setEnvironmentId(environmentId)
+                  }}
+                  formatOptionLabel={renderEnvOption}
+                />
+                <div className='text-muted fs-small mt-2'>
+                  Last synced:{' '}
+                  {selectedMembership
+                    ? moment(selectedMembership.last_synced_at).format(
+                        'Do MMM YYYY HH:mm:ss',
+                      )
+                    : '—'}
+                </div>
+              </>
             }
           />
           <PanelSearch
diff --git a/frontend/web/components/segments/SegmentMembershipBadge.tsx b/frontend/web/components/segments/SegmentMembershipBadge.tsx
new file mode 100644
index 000000000000..ce4423d49071
--- /dev/null
+++ b/frontend/web/components/segments/SegmentMembershipBadge.tsx
@@ -0,0 +1,84 @@
+import React, { FC } from 'react'
+
+import { Environment, SegmentMembership } from 'common/types/responses'
+import Tooltip from 'components/Tooltip'
+import UsersIcon from 'components/icons/UsersIcon'
+
+const shortAgo = (iso: string): string => {
+  const diffSec = Math.max(0, Math.round((Date.now() - new Date(iso).getTime()) / 1000))
+  if (diffSec < 60) return `${diffSec}s ago`
+  const diffMin = Math.round(diffSec / 60)
+  if (diffMin < 60) return `${diffMin}m ago`
+  const diffHr = Math.round(diffMin / 60)
+  if (diffHr < 24) return `${diffHr}h ago`
+  return `${Math.round(diffHr / 24)}d ago`
+}
+
+const formatTooltip = (count: number, lastSyncedAt: string | undefined): string => {
+  const noun = count === 1 ? 'identity' : 'identities'
+  const base = `${count} ${noun}`
+  return lastSyncedAt ? `${base} — last synced ~${shortAgo(lastSyncedAt)}` : base
+}
+
+type ChipProps = {
+  count: number
+  dataTest?: string
+  tooltip: string
+}
+
+const Chip: FC<ChipProps> = ({ count, dataTest, tooltip }) => (
+  <Tooltip
+    plainText
+    delayShow={100}
+    title={
+      <span
+        className='chip chip--xs bg-primary text-white ms-3'
+        style={{ border: 'none', alignSelf: 'center', verticalAlign: 'middle' }}
+        data-test={dataTest}
+      >
+        <UsersIcon className='chip-svg-icon' />
+        <span>{count}</span>
+      </span>
+    }
+  >
+    {tooltip}
+  </Tooltip>
+)
+
+type TotalProps = {
+  memberships: SegmentMembership[] | undefined
+}
+
+export const SegmentMembershipTotalBadge: FC<TotalProps> = ({ memberships }) => {
+  if (!memberships?.length) {
+    return null
+  }
+  const total = memberships.reduce((sum, m) => sum + m.count, 0)
+  const latest = memberships.reduce(
+    (acc, m) => (!acc || m.last_synced_at > acc ? m.last_synced_at : acc),
+    '',
+  )
+  return (
+    <Chip
+      count={total}
+      tooltip={formatTooltip(total, latest || undefined)}
+      dataTest='segment-membership-total'
+    />
+  )
+}
+
+type EnvProps = {
+  membership: SegmentMembership
+  environment: Environment
+}
+
+export const SegmentMembershipEnvBadge: FC<EnvProps> = ({
+  environment,
+  membership,
+}) => (
+  <Chip
+    count={membership.count}
+    tooltip={formatTooltip(membership.count, membership.last_synced_at)}
+    dataTest={`segment-membership-${environment.api_key}`}
+  />
+)
diff --git a/frontend/web/components/segments/SegmentRow/SegmentRow.tsx b/frontend/web/components/segments/SegmentRow/SegmentRow.tsx
index a965bc95ebf0..fbcae5e35c14 100644
--- a/frontend/web/components/segments/SegmentRow/SegmentRow.tsx
+++ b/frontend/web/components/segments/SegmentRow/SegmentRow.tsx
@@ -5,6 +5,7 @@ import { useHasPermission } from 'common/providers/Permission'
 
 import { Segment } from 'common/types/responses'
 import SegmentAction from './components/SegmentAction'
+import { SegmentMembershipTotalBadge } from 'components/segments/SegmentMembershipBadge'
 import ConfirmCloneSegment from 'components/modals/ConfirmCloneSegment'
 import { useCloneSegmentMutation } from 'common/services/useSegment'
 import { handleRemoveSegment } from 'components/modals/ConfirmRemoveSegment'
@@ -81,6 +82,7 @@ const SegmentRow: FC<SegmentRowProps> = ({ index, projectId, segment }) => {
           {feature && (
             <div className='chip chip--xs ml-2'>Feature-Specific</div>
           )}
+          <SegmentMembershipTotalBadge memberships={segment.memberships} />
         </Row>
         <div className='list-item-subtitle mt-1'>
           {description || 'No description'}
diff --git a/frontend/web/project/project-components.js b/frontend/web/project/project-components.js
index 696c7e0e0a9d..0dcef7ea6bb5 100644
--- a/frontend/web/project/project-components.js
+++ b/frontend/web/project/project-components.js
@@ -92,6 +92,15 @@ global.ToggleChip = ToggleChip
 
 // Custom Option component to show the tick mark next to selected option in the dropdown
 const Option = (props) => {
+  const { formatOptionLabel } = props.selectProps
+  const labelContent = formatOptionLabel
+    ? formatOptionLabel(props.data, { context: 'menu' })
+    : (
+        <>
+          {props.data.label}
+          <div className='text-small'>{props.data.description}</div>
+        </>
+      )
   return (
     <components.Option {...props}>
       <div
@@ -99,10 +108,7 @@ const Option = (props) => {
           props.data.isDisabled ? 'text-muted cursor-not-allowed' : ''
         }`}
       >
-        <div>
-          {props.data.label}
-          <div className='text-small'>{props.data.description}</div>
-        </div>
+        <div>{labelContent}</div>
         {props.isSelected && (
           <IonIcon icon={checkmarkCircle} className='text-primary' />
         )}
diff --git a/frontend/web/styles/components/_chip.scss b/frontend/web/styles/components/_chip.scss
index d4e0313bb5c1..0f3e07a99d85 100644
--- a/frontend/web/styles/components/_chip.scss
+++ b/frontend/web/styles/components/_chip.scss
@@ -27,7 +27,7 @@
 .chip {
   display: flex;
   align-items: center;
-  align-self: flex-start !important;
+  align-self: flex-start;
   background-color: $primary-alfa-8;
   border: 1px solid $primary-alfa-24;
   padding: 5px 12px;