diff --git a/prowler/CHANGELOG.md b/prowler/CHANGELOG.md
index bb4053e3b8..b14ef2de8f 100644
--- a/prowler/CHANGELOG.md
+++ b/prowler/CHANGELOG.md
@@ -9,6 +9,7 @@ All notable changes to the **Prowler SDK** are documented in this file.
 - `securityhub_delegated_admin_enabled_all_regions` check for AWS provider, verifying that Security Hub has a delegated administrator, is active in all opted-in regions, and has organization auto-enable on [(#11259)](https://github.com/prowler-cloud/prowler/pull/11259)
 - `config_delegated_admin_and_org_aggregator_all_regions` check for AWS provider, verifying that AWS Config has a delegated administrator and an organization aggregator covering all AWS regions [(#11259)](https://github.com/prowler-cloud/prowler/pull/11259)
 - `sagemaker_clarify_exists` check for AWS provider [(#11211)](https://github.com/prowler-cloud/prowler/pull/11211)
+- `cloudsql_instance_high_availability_enabled` check for GCP provider, verifying Cloud SQL primary instances use `REGIONAL` availability for automatic zone failover [(#11024)](https://github.com/prowler-cloud/prowler/pull/11024)
 - `identity_storage_service_level_admins_scoped` check for OCI provider CIS 3.1 control 1.15, ensuring storage service-level administrators exclude delete permissions [(#11523)](https://github.com/prowler-cloud/prowler/pull/11523)
 
 ---
diff --git a/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/__init__.py b/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.metadata.json b/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.metadata.json
new file mode 100644
index 0000000000..3e66f9cdd3
--- /dev/null
+++ b/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.metadata.json
@@ -0,0 +1,38 @@
+{
+  "Provider": "gcp",
+  "CheckID": "cloudsql_instance_high_availability_enabled",
+  "CheckTitle": "Cloud SQL instance has high availability (REGIONAL) configured",
+  "CheckType": [],
+  "ServiceName": "cloudsql",
+  "SubServiceName": "",
+  "ResourceIdTemplate": "",
+  "Severity": "medium",
+  "ResourceType": "sqladmin.googleapis.com/Instance",
+  "Description": "Ensures that Cloud SQL instances have high availability configured by setting availabilityType to REGIONAL. A REGIONAL instance maintains a standby replica in a different zone within the same region and automatically fails over on zone-level outages.",
+  "Risk": "Instances with ZONAL availability have no standby replica. A zone-level outage will cause database downtime until manual recovery, violating availability requirements and potentially breaching SLAs and ISMS-P 2.12.1 disaster preparedness controls.",
+  "RelatedUrl": "",
+  "AdditionalURLs": [
+    "https://cloud.google.com/sql/docs/postgres/high-availability",
+    "https://cloud.google.com/sql/docs/sqlserver/high-availability"
+  ],
+  "Remediation": {
+    "Code": {
+      "CLI": "gcloud sql instances patch <INSTANCE_NAME> --availability-type=REGIONAL",
+      "NativeIaC": "",
+      "Other": "1. Go to Google Cloud Console > SQL > Instances.\n2. Click the instance name, then Edit.\n3. Under Availability, select Multiple zones (Highly available).\n4. Click Save.",
+      "Terraform": "```hcl\nresource \"google_sql_database_instance\" \"example\" {\n  name             = \"<instance_name>\"\n  database_version = \"POSTGRES_15\"\n  region           = \"<region>\"\n\n  settings {\n    tier = \"db-custom-2-7680\"\n\n    availability_type = \"REGIONAL\"  # Critical: enables HA standby replica\n\n    backup_configuration {\n      enabled    = true\n      start_time = \"02:00\"\n    }\n  }\n}\n```"
+    },
+    "Recommendation": {
+      "Text": "Set availabilityType to REGIONAL for all production Cloud SQL instances. This creates a standby replica in a different zone and enables automatic failover, reducing RTO in the event of a zone outage.",
+      "Url": "https://hub.prowler.com/check/cloudsql_instance_high_availability_enabled"
+    }
+  },
+  "Categories": [
+    "resilience"
+  ],
+  "DependsOn": [],
+  "RelatedTo": [
+    "cloudsql_instance_automated_backups"
+  ],
+  "Notes": "Enabling HA increases instance cost approximately 2x due to the standby replica. ZONAL instances are acceptable for non-production workloads where downtime is tolerable."
+}
diff --git a/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.py b/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.py
new file mode 100644
index 0000000000..37bf576345
--- /dev/null
+++ b/prowler/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled.py
@@ -0,0 +1,41 @@
+from prowler.lib.check.models import Check, Check_Report_GCP
+from prowler.providers.gcp.services.cloudsql.cloudsql_client import cloudsql_client
+
+
+class cloudsql_instance_high_availability_enabled(Check):
+    """Check that Cloud SQL primary instances are configured for high availability.
+
+    Verifies that each Cloud SQL primary instance has `availabilityType` set to
+    `REGIONAL`, which provisions a standby replica in a different zone within
+    the same region and enables automatic failover on zone-level outages. Read
+    replicas are skipped because they inherit availability from their primary.
+    """
+
+    def execute(self) -> list[Check_Report_GCP]:
+        """Execute the high availability check across all Cloud SQL instances.
+
+        Returns:
+            A list of `Check_Report_GCP` findings, one per Cloud SQL primary
+            instance. Status is `PASS` when `availability_type == "REGIONAL"`
+            and `FAIL` otherwise.
+        """
+        findings = []
+        for instance in cloudsql_client.instances:
+            if instance.instance_type != "CLOUD_SQL_INSTANCE":
+                continue
+            report = Check_Report_GCP(metadata=self.metadata(), resource=instance)
+            if instance.availability_type == "REGIONAL":
+                report.status = "PASS"
+                report.status_extended = (
+                    f"Database instance {instance.name} has high availability "
+                    f"(REGIONAL) configured."
+                )
+            else:
+                report.status = "FAIL"
+                report.status_extended = (
+                    f"Database instance {instance.name} does not have high "
+                    f"availability configured (current: "
+                    f"{instance.availability_type})."
+                )
+            findings.append(report)
+        return findings
diff --git a/prowler/providers/gcp/services/cloudsql/cloudsql_service.py b/prowler/providers/gcp/services/cloudsql/cloudsql_service.py
index 137169999a..1fe706bb02 100644
--- a/prowler/providers/gcp/services/cloudsql/cloudsql_service.py
+++ b/prowler/providers/gcp/services/cloudsql/cloudsql_service.py
@@ -46,6 +46,9 @@ class CloudSQL(GCPService):
                                     "authorizedNetworks", []
                                 ),
                                 flags=settings.get("databaseFlags", []),
+                                availability_type=settings.get(
+                                    "availabilityType", "ZONAL"
+                                ),
                                 instance_type=instance.get(
                                     "instanceType", "CLOUD_SQL_INSTANCE"
                                 ),
@@ -76,6 +79,7 @@ class Instance(BaseModel):
     ssl_mode: str
     automated_backups: bool
     flags: list
+    availability_type: str = "ZONAL"
     instance_type: str = "CLOUD_SQL_INSTANCE"
     cmek_key_name: Optional[str] = None
     project_id: str
diff --git a/tests/providers/gcp/gcp_fixtures.py b/tests/providers/gcp/gcp_fixtures.py
index ba6480ee22..1abcaf5bf0 100644
--- a/tests/providers/gcp/gcp_fixtures.py
+++ b/tests/providers/gcp/gcp_fixtures.py
@@ -722,6 +722,7 @@ def mock_api_instances_calls(client: MagicMock, service: str):
                         },
                         "backupConfiguration": {"enabled": True},
                         "databaseFlags": [],
+                        "availabilityType": "REGIONAL",
                     },
                 },
                 {
@@ -737,6 +738,7 @@ def mock_api_instances_calls(client: MagicMock, service: str):
                         },
                         "backupConfiguration": {"enabled": False},
                         "databaseFlags": [],
+                        "availabilityType": "ZONAL",
                     },
                 },
             ]
diff --git a/tests/providers/gcp/services/cloudsql/cloudsql_instance_cmek_encryption_enabled/__init__.py b/tests/providers/gcp/services/cloudsql/cloudsql_instance_cmek_encryption_enabled/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/__init__.py b/tests/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled_test.py b/tests/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled_test.py
new file mode 100644
index 0000000000..82c49fb89e
--- /dev/null
+++ b/tests/providers/gcp/services/cloudsql/cloudsql_instance_high_availability_enabled/cloudsql_instance_high_availability_enabled_test.py
@@ -0,0 +1,205 @@
+from unittest import mock
+
+from tests.providers.gcp.gcp_fixtures import (
+    GCP_EU1_LOCATION,
+    GCP_PROJECT_ID,
+    set_mocked_gcp_provider,
+)
+
+
+class Test_cloudsql_instance_high_availability_enabled:
+    """Tests for the cloudsql_instance_high_availability_enabled check."""
+
+    def test_no_instances(self):
+        """No Cloud SQL instances → no findings."""
+        cloudsql_client = mock.MagicMock()
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_gcp_provider(),
+            ),
+            mock.patch(
+                "prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled.cloudsql_client",
+                new=cloudsql_client,
+            ),
+        ):
+            from prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled import (
+                cloudsql_instance_high_availability_enabled,
+            )
+
+            cloudsql_client.instances = []
+            check = cloudsql_instance_high_availability_enabled()
+            result = check.execute()
+            assert len(result) == 0
+
+    def test_instance_ha_enabled(self):
+        """A REGIONAL primary instance → PASS."""
+        cloudsql_client = mock.MagicMock()
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_gcp_provider(),
+            ),
+            mock.patch(
+                "prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled.cloudsql_client",
+                new=cloudsql_client,
+            ),
+        ):
+            from prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled import (
+                cloudsql_instance_high_availability_enabled,
+            )
+            from prowler.providers.gcp.services.cloudsql.cloudsql_service import (
+                Instance,
+            )
+
+            cloudsql_client.instances = [
+                Instance(
+                    name="db-ha",
+                    version="POSTGRES_15",
+                    ip_addresses=[],
+                    region=GCP_EU1_LOCATION,
+                    public_ip=False,
+                    require_ssl=False,
+                    ssl_mode="ENCRYPTED_ONLY",
+                    automated_backups=True,
+                    authorized_networks=[],
+                    flags=[],
+                    project_id=GCP_PROJECT_ID,
+                    availability_type="REGIONAL",
+                )
+            ]
+            check = cloudsql_instance_high_availability_enabled()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "PASS"
+            assert result[0].resource_id == "db-ha"
+            assert result[0].location == GCP_EU1_LOCATION
+            assert result[0].project_id == GCP_PROJECT_ID
+
+    def test_instance_ha_disabled(self):
+        """A ZONAL primary instance → FAIL with current availability in status_extended."""
+        cloudsql_client = mock.MagicMock()
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_gcp_provider(),
+            ),
+            mock.patch(
+                "prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled.cloudsql_client",
+                new=cloudsql_client,
+            ),
+        ):
+            from prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled import (
+                cloudsql_instance_high_availability_enabled,
+            )
+            from prowler.providers.gcp.services.cloudsql.cloudsql_service import (
+                Instance,
+            )
+
+            cloudsql_client.instances = [
+                Instance(
+                    name="db-zonal",
+                    version="POSTGRES_15",
+                    ip_addresses=[],
+                    region=GCP_EU1_LOCATION,
+                    public_ip=False,
+                    require_ssl=False,
+                    ssl_mode="ENCRYPTED_ONLY",
+                    automated_backups=True,
+                    authorized_networks=[],
+                    flags=[],
+                    project_id=GCP_PROJECT_ID,
+                    availability_type="ZONAL",
+                )
+            ]
+            check = cloudsql_instance_high_availability_enabled()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert "ZONAL" in result[0].status_extended
+            assert result[0].resource_id == "db-zonal"
+            assert result[0].location == GCP_EU1_LOCATION
+            assert result[0].project_id == GCP_PROJECT_ID
+
+    def test_read_replica_skipped(self):
+        """Read replicas (instance_type != CLOUD_SQL_INSTANCE) are skipped."""
+        cloudsql_client = mock.MagicMock()
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_gcp_provider(),
+            ),
+            mock.patch(
+                "prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled.cloudsql_client",
+                new=cloudsql_client,
+            ),
+        ):
+            from prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled import (
+                cloudsql_instance_high_availability_enabled,
+            )
+            from prowler.providers.gcp.services.cloudsql.cloudsql_service import (
+                Instance,
+            )
+
+            cloudsql_client.instances = [
+                Instance(
+                    name="db-replica",
+                    version="POSTGRES_15",
+                    ip_addresses=[],
+                    region=GCP_EU1_LOCATION,
+                    public_ip=False,
+                    require_ssl=False,
+                    ssl_mode="ENCRYPTED_ONLY",
+                    automated_backups=True,
+                    authorized_networks=[],
+                    flags=[],
+                    project_id=GCP_PROJECT_ID,
+                    availability_type="ZONAL",
+                    instance_type="READ_REPLICA_INSTANCE",
+                )
+            ]
+            check = cloudsql_instance_high_availability_enabled()
+            result = check.execute()
+            assert len(result) == 0
+
+    def test_instance_default_availability_type_fails(self):
+        """An instance missing availabilityType defaults to ZONAL (service layer) and must FAIL."""
+        cloudsql_client = mock.MagicMock()
+        with (
+            mock.patch(
+                "prowler.providers.common.provider.Provider.get_global_provider",
+                return_value=set_mocked_gcp_provider(),
+            ),
+            mock.patch(
+                "prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled.cloudsql_client",
+                new=cloudsql_client,
+            ),
+        ):
+            from prowler.providers.gcp.services.cloudsql.cloudsql_instance_high_availability_enabled.cloudsql_instance_high_availability_enabled import (
+                cloudsql_instance_high_availability_enabled,
+            )
+            from prowler.providers.gcp.services.cloudsql.cloudsql_service import (
+                Instance,
+            )
+
+            cloudsql_client.instances = [
+                Instance(
+                    name="db-default",
+                    version="POSTGRES_15",
+                    ip_addresses=[],
+                    region=GCP_EU1_LOCATION,
+                    public_ip=False,
+                    require_ssl=False,
+                    ssl_mode="ENCRYPTED_ONLY",
+                    automated_backups=True,
+                    authorized_networks=[],
+                    flags=[],
+                    project_id=GCP_PROJECT_ID,
+                    # availability_type omitted → model default "ZONAL"
+                )
+            ]
+            check = cloudsql_instance_high_availability_enabled()
+            result = check.execute()
+            assert len(result) == 1
+            assert result[0].status == "FAIL"
+            assert "ZONAL" in result[0].status_extended