diff --git a/src/sentry/seer/agent/tools.py b/src/sentry/seer/agent/tools.py
index 038ec177e2bd..6158e3792a0a 100644
--- a/src/sentry/seer/agent/tools.py
+++ b/src/sentry/seer/agent/tools.py
@@ -47,7 +47,7 @@
     get_retention_boundary,
 )
 from sentry.seer.autofix.autofix import get_all_tags_overview
-from sentry.seer.constants import SEER_SUPPORTED_SCM_PROVIDERS
+from sentry.seer.seer_setup import get_supported_scm_providers
 from sentry.seer.sentry_data_models import EAPTrace
 from sentry.services.eventstore.models import Event, GroupEvent
 from sentry.snuba.dataset import Dataset
@@ -684,6 +684,9 @@ def get_repository_definition(
         dict with RepoDefinition fields if found, None otherwise. Includes external_id
         which should be stored for future lookups.
     """
+    organization = Organization.objects.get_from_cache(id=organization_id)
+    supported_providers = get_supported_scm_providers(organization)
+
     repo: Repository | None = None
 
     if external_id:
@@ -691,7 +694,7 @@ def get_repository_definition(
             organization_id=organization_id,
             external_id=external_id,
             status=ObjectStatus.ACTIVE,
-            provider__in=SEER_SUPPORTED_SCM_PROVIDERS,
+            provider__in=supported_providers,
         ).first()
 
     if not repo:
@@ -707,7 +710,7 @@ def get_repository_definition(
             organization_id=organization_id,
             name=repo_full_name,
             status=ObjectStatus.ACTIVE,
-            provider__in=SEER_SUPPORTED_SCM_PROVIDERS,
+            provider__in=supported_providers,
         ).first()
 
     if not repo:
diff --git a/src/sentry/seer/autofix/utils.py b/src/sentry/seer/autofix/utils.py
index bd986916bb2c..4b194c247c88 100644
--- a/src/sentry/seer/autofix/utils.py
+++ b/src/sentry/seer/autofix/utils.py
@@ -34,7 +34,6 @@
 from sentry.net.http import connection_from_url
 from sentry.projectoptions.defaults import SEER_PROJECT_PREFERENCE_OPTION_KEYS
 from sentry.seer.autofix.constants import AutofixAutomationTuningSettings, AutofixStatus
-from sentry.seer.constants import SEER_SUPPORTED_SCM_PROVIDERS
 from sentry.seer.models import (
     AutofixHandoffPoint,
     BranchOverride,
@@ -48,6 +47,7 @@
     SeerProjectRepository,
     SeerProjectRepositoryBranchOverride,
 )
+from sentry.seer.seer_setup import get_supported_scm_providers
 from sentry.seer.signed_seer_api import SeerViewerContext, make_signed_seer_api_request
 from sentry.utils.cache import cache
 from sentry.utils.outcomes import Outcome, track_outcome
@@ -830,7 +830,7 @@ def get_autofix_repos_from_project_code_mappings(
             and repo.integration_id is not None
             and repo.external_id
             and repo.provider
-            and repo.provider in SEER_SUPPORTED_SCM_PROVIDERS
+            and repo.provider in get_supported_scm_providers(project.organization)
         ):
             repo_dict = {
                 "repository_id": repo.id,
diff --git a/src/sentry/seer/constants.py b/src/sentry/seer/constants.py
index 81e1a0fa791c..a421cf24ea94 100644
--- a/src/sentry/seer/constants.py
+++ b/src/sentry/seer/constants.py
@@ -6,8 +6,10 @@
 SeerSCMProvider = Literal[
     "integrations:github",
     "integrations:github_enterprise",
+    "integrations:gitlab",
     "github",
     "github_enterprise",
+    "gitlab",
 ]
 
 # Supported repository providers for Seer features
@@ -17,3 +19,8 @@
     IntegrationProviderSlug.GITHUB.value,
     IntegrationProviderSlug.GITHUB_ENTERPRISE.value,
 ]
+
+SEER_GITLAB_SCM_PROVIDERS = [
+    "integrations:gitlab",
+    IntegrationProviderSlug.GITLAB.value,
+]
diff --git a/src/sentry/seer/endpoints/organization_autofix_automation_settings.py b/src/sentry/seer/endpoints/organization_autofix_automation_settings.py
index 9f5ee71d85b3..b9ed7af3d514 100644
--- a/src/sentry/seer/endpoints/organization_autofix_automation_settings.py
+++ b/src/sentry/seer/endpoints/organization_autofix_automation_settings.py
@@ -30,8 +30,8 @@
     deduplicate_repositories,
     default_seer_project_preference,
 )
-from sentry.seer.constants import SEER_SUPPORTED_SCM_PROVIDERS
 from sentry.seer.models import SeerProjectPreference, SeerRepoDefinition
+from sentry.seer.seer_setup import get_supported_scm_providers
 from sentry.seer.utils import filter_repo_by_provider
 
 
@@ -66,10 +66,11 @@ class RepositorySerializer(CamelSnakeSerializer):
     provider_raw = serializers.CharField(required=False, allow_null=True)
 
     def validate_provider(self, value):
-        if value not in SEER_SUPPORTED_SCM_PROVIDERS:
-            supported = ", ".join(sorted(SEER_SUPPORTED_SCM_PROVIDERS))
+        supported = get_supported_scm_providers(self.context.get("organization"))
+        if value not in supported:
+            supported_str = ", ".join(sorted(supported))
             raise serializers.ValidationError(
-                f'"{value}" is not a supported Seer provider. Supported providers: {supported}'
+                f'"{value}" is not a supported Seer provider. Supported providers: {supported_str}'
             )
         return value
 
@@ -110,7 +111,7 @@ def to_internal_value(self, data):
 
             serialized_repos = []
             for repo_data in repos_data:
-                repo_serializer = RepositorySerializer(data=repo_data)
+                repo_serializer = RepositorySerializer(data=repo_data, context=self.context)
                 if not repo_serializer.is_valid():
                     raise serializers.ValidationError(
                         {f"project_{project_id_str}": repo_serializer.errors}
diff --git a/src/sentry/seer/endpoints/project_seer_preferences.py b/src/sentry/seer/endpoints/project_seer_preferences.py
index 8ff6db282acc..3ffa7d6bf3e0 100644
--- a/src/sentry/seer/endpoints/project_seer_preferences.py
+++ b/src/sentry/seer/endpoints/project_seer_preferences.py
@@ -90,7 +90,10 @@ class ProjectSeerPreferencesEndpoint(ProjectEndpoint):
     )
 
     def post(self, request: Request, project: Project) -> Response:
-        serializer = ProjectSeerPreferencesSerializer(data=request.data)
+        serializer = ProjectSeerPreferencesSerializer(
+            data=request.data,
+            context={"organization": project.organization},
+        )
         serializer.is_valid(raise_exception=True)
 
         for repo_data in serializer.validated_data.get("repositories", []):
diff --git a/src/sentry/seer/endpoints/seer_rpc.py b/src/sentry/seer/endpoints/seer_rpc.py
index ff536aa0f0ea..30f6e279b36e 100644
--- a/src/sentry/seer/endpoints/seer_rpc.py
+++ b/src/sentry/seer/endpoints/seer_rpc.py
@@ -112,11 +112,12 @@
     clear_preference_automation_handoff,
     read_preference_from_sentry_db,
 )
-from sentry.seer.constants import SEER_SUPPORTED_SCM_PROVIDERS, SeerSCMProvider
+from sentry.seer.constants import SeerSCMProvider
 from sentry.seer.entrypoints.operator import SeerAutofixOperator, process_autofix_updates
 from sentry.seer.fetch_issues import by_error_type, by_function_name, by_text_query, utils
 from sentry.seer.fetch_issues.utils import NoProjectsForRepoError, get_repo_and_projects
 from sentry.seer.issue_detection import create_issue_occurrence
+from sentry.seer.seer_setup import get_supported_scm_providers
 from sentry.seer.utils import filter_repo_by_provider
 from sentry.sentry_apps.metrics import SentryAppEventType
 from sentry.sentry_apps.tasks.sentry_apps import broadcast_webhooks_for_organization
@@ -704,7 +705,8 @@ def validate_repo(
     if not repo:
         return {"valid": False, "reason": "repository_not_found"}
 
-    if repo.provider not in SEER_SUPPORTED_SCM_PROVIDERS:
+    organization = Organization.objects.get_from_cache(id=organization_id)
+    if repo.provider not in get_supported_scm_providers(organization):
         return {"valid": False, "reason": "unsupported_provider"}
 
     return {"valid": True, "integration_id": repo.integration_id}
@@ -737,7 +739,8 @@ def get_repo_installation_id(
     if not repo:
         return {"error": "repository_not_found"}
 
-    if repo.provider not in SEER_SUPPORTED_SCM_PROVIDERS:
+    organization = Organization.objects.get_from_cache(id=organization_id)
+    if repo.provider not in get_supported_scm_providers(organization):
         return {"error": "unsupported_provider"}
 
     if repo.integration_id is None:
@@ -816,15 +819,25 @@ def check_repository_integrations_status(*, repository_integrations: list[dict[s
             external_id=item["external_id"],
         )
 
+    org_ids = {item["organization_id"] for item in repository_integrations}
+    orgs_by_id = {org.id: org for org in Organization.objects.filter(id__in=org_ids)}
+    supported_by_org: dict[int, set[str]] = {
+        org_id: set(get_supported_scm_providers(org)) for org_id, org in orgs_by_id.items()
+    }
+    all_supported_providers: set[str] = set()
+    for providers in supported_by_org.values():
+        all_supported_providers.update(providers)
+
     existing_repos = Repository.objects.filter(
-        q_objects, status=ObjectStatus.ACTIVE, provider__in=SEER_SUPPORTED_SCM_PROVIDERS
+        q_objects, status=ObjectStatus.ACTIVE, provider__in=all_supported_providers
     ).values_list("organization_id", "provider", "integration_id", "external_id")
 
     existing_map: dict[tuple, int | None] = {}
 
     for org_id, provider, integration_id, external_id in existing_repos:
+        if provider not in supported_by_org.get(org_id, set()):
+            continue
         key = (org_id, provider, external_id)
-        # If multiple repos match (shouldn't happen), keep the first one
         if key not in existing_map:
             existing_map[key] = integration_id
 
diff --git a/src/sentry/seer/seer_setup.py b/src/sentry/seer/seer_setup.py
index 944375854f9c..1b5bf05d951c 100644
--- a/src/sentry/seer/seer_setup.py
+++ b/src/sentry/seer/seer_setup.py
@@ -3,10 +3,18 @@
 from sentry import features
 from sentry.models.organization import Organization
 from sentry.organizations.services.organization.model import RpcOrganization
+from sentry.seer.constants import SEER_GITLAB_SCM_PROVIDERS, SEER_SUPPORTED_SCM_PROVIDERS
 from sentry.users.models.user import User
 from sentry.users.services.user.model import RpcUser
 
 
+def get_supported_scm_providers(organization: Organization | None = None) -> list[str]:
+    providers = list(SEER_SUPPORTED_SCM_PROVIDERS)
+    if organization is not None and features.has("organizations:seer-gitlab-support", organization):
+        providers.extend(SEER_GITLAB_SCM_PROVIDERS)
+    return providers
+
+
 def has_seer_access(
     organization: Organization | RpcOrganization,
     actor: User | AnonymousUser | RpcUser | None = None,
diff --git a/tests/sentry/autofix/test_utils.py b/tests/sentry/autofix/test_utils.py
index 6e8f6e72c4d5..5f5e2399e2e6 100644
--- a/tests/sentry/autofix/test_utils.py
+++ b/tests/sentry/autofix/test_utils.py
@@ -20,6 +20,7 @@
 )
 from sentry.seer.models import SeerPermissionError
 from sentry.testutils.cases import TestCase
+from sentry.testutils.helpers.features import with_feature
 from sentry.testutils.helpers.options import override_options
 
 
@@ -74,6 +75,32 @@ def test_filters_out_unsupported_providers(self) -> None:
         assert len(repos) == 1
         assert repos[0]["provider"] == "integrations:github"
 
+    @with_feature("organizations:seer-gitlab-support")
+    def test_includes_gitlab_repos_with_feature_flag(self) -> None:
+        project = self.create_project()
+        github_repo = self.create_repo(
+            name="getsentry/sentry",
+            provider="integrations:github",
+            external_id="123",
+            integration_id=234,
+        )
+        self.create_code_mapping(project=project, repo=github_repo)
+
+        gitlab_repo = self.create_repo(
+            name="getsentry/sentry-gitlab",
+            provider="integrations:gitlab",
+            external_id="456",
+            integration_id=345,
+        )
+        self.create_code_mapping(
+            project=project, repo=gitlab_repo, stack_root="gitlab/", source_root="src/gitlab/"
+        )
+
+        repos = get_autofix_repos_from_project_code_mappings(project)
+        assert len(repos) == 2
+        providers = {r["provider"] for r in repos}
+        assert providers == {"integrations:github", "integrations:gitlab"}
+
     def test_filters_out_disabled_repos(self) -> None:
         project = self.create_project()
         active_repo = self.create_repo(
diff --git a/tests/sentry/seer/endpoints/test_project_seer_preferences.py b/tests/sentry/seer/endpoints/test_project_seer_preferences.py
index 38063dcd4e69..ca153727e76f 100644
--- a/tests/sentry/seer/endpoints/test_project_seer_preferences.py
+++ b/tests/sentry/seer/endpoints/test_project_seer_preferences.py
@@ -5,6 +5,7 @@
 from sentry.models.repository import Repository
 from sentry.seer.models.project_repository import SeerProjectRepository
 from sentry.testutils.cases import APITestCase
+from sentry.testutils.helpers.features import with_feature
 
 
 class ProjectSeerPreferencesEndpointTest(APITestCase):
@@ -471,3 +472,67 @@ def test_post_rejects_unsupported_repo_provider(self) -> None:
 
         assert response.status_code == 400
         assert SeerProjectRepository.objects.filter(project=self.project).count() == 0
+
+    @with_feature("organizations:seer-gitlab-support")
+    def test_post_accepts_gitlab_repo_with_feature_flag(self) -> None:
+        gitlab_repo = self.create_repo(
+            project=self.project,
+            name="getsentry/sentry-gitlab",
+            provider="integrations:gitlab",
+            external_id="789",
+            integration_id=456,
+        )
+
+        request_data = {
+            "repositories": [
+                {
+                    "organization_id": self.org.id,
+                    "integration_id": "456",
+                    "provider": "integrations:gitlab",
+                    "owner": "getsentry",
+                    "name": "sentry-gitlab",
+                    "external_id": "789",
+                }
+            ],
+        }
+
+        response = self.client.post(self.url, data=request_data)
+
+        assert response.status_code == 204
+        seer_repos = list(
+            SeerProjectRepository.objects.filter(project=self.project).select_related("repository")
+        )
+        assert len(seer_repos) == 1
+        assert seer_repos[0].repository_id == gitlab_repo.id
+
+    @with_feature("organizations:seer-gitlab-support")
+    def test_post_accepts_gitlab_bare_provider_with_feature_flag(self) -> None:
+        gitlab_repo = self.create_repo(
+            project=self.project,
+            name="getsentry/sentry-gitlab",
+            provider="integrations:gitlab",
+            external_id="789",
+            integration_id=456,
+        )
+
+        request_data = {
+            "repositories": [
+                {
+                    "organization_id": self.org.id,
+                    "integration_id": "456",
+                    "provider": "gitlab",
+                    "owner": "getsentry",
+                    "name": "sentry-gitlab",
+                    "external_id": "789",
+                }
+            ],
+        }
+
+        response = self.client.post(self.url, data=request_data)
+
+        assert response.status_code == 204
+        seer_repos = list(
+            SeerProjectRepository.objects.filter(project=self.project).select_related("repository")
+        )
+        assert len(seer_repos) == 1
+        assert seer_repos[0].repository_id == gitlab_repo.id