diff --git a/.changeset/twelve-sides-cheer.md b/.changeset/twelve-sides-cheer.md
new file mode 100644
index 00000000000..163841dae07
--- /dev/null
+++ b/.changeset/twelve-sides-cheer.md
@@ -0,0 +1,5 @@
+---
+'@clerk/backend': patch
+---
+
+Fix `attributeMapping` field in the `CreateSamlConnectionParams` and `UpdateSamlConnectionParams` types.
diff --git a/packages/backend/src/api/__tests__/SamlConnectionApi.test.ts b/packages/backend/src/api/__tests__/SamlConnectionApi.test.ts
index c275927c45e..94b8b7987ce 100644
--- a/packages/backend/src/api/__tests__/SamlConnectionApi.test.ts
+++ b/packages/backend/src/api/__tests__/SamlConnectionApi.test.ts
@@ -73,4 +73,148 @@ describe('SamlConnectionAPI', () => {
       expect(response.totalCount).toBe(1);
     });
   });
+
+  describe('createSamlConnection', () => {
+    it('successfully creates a SAML connection', async () => {
+      const mockSamlConnectionResponse = {
+        object: 'saml_connection',
+        id: 'samlc_123',
+        name: 'Test Connection',
+        provider: 'saml_custom',
+        domain: 'test.example.com',
+        organization_id: 'org_123',
+        created_at: 1672531200000,
+        updated_at: 1672531200000,
+        active: true,
+        sync_user_attributes: false,
+        allow_subdomains: false,
+        allow_idp_initiated: false,
+        idp_entity_id: 'entity_123',
+        idp_sso_url: 'https://idp.example.com/sso',
+        idp_certificate: 'cert_data',
+        idp_metadata_url: null,
+        idp_metadata: null,
+        attribute_mapping: {
+          user_id: 'userId',
+          email_address: 'email',
+          first_name: 'firstName',
+          last_name: 'lastName',
+        },
+      };
+
+      server.use(
+        http.post(
+          'https://api.clerk.test/v1/saml_connections',
+          validateHeaders(async ({ request }) => {
+            const body = await request.json();
+
+            expect(body).toEqual({
+              name: 'Test Connection',
+              provider: 'saml_custom',
+              domain: 'test.example.com',
+              attribute_mapping: {
+                user_id: 'userId',
+                email_address: 'email',
+                first_name: 'firstName',
+                last_name: 'lastName',
+              },
+            });
+            return HttpResponse.json(mockSamlConnectionResponse);
+          }),
+        ),
+      );
+
+      const response = await apiClient.samlConnections.createSamlConnection({
+        name: 'Test Connection',
+        provider: 'saml_custom',
+        domain: 'test.example.com',
+        attributeMapping: {
+          user_id: 'userId',
+          email_address: 'email',
+          first_name: 'firstName',
+          last_name: 'lastName',
+        },
+      });
+
+      expect(response.id).toBe('samlc_123');
+      expect(response.name).toBe('Test Connection');
+      expect(response.organizationId).toBe('org_123');
+    });
+  });
+
+  describe('updateSamlConnection', () => {
+    it('successfully updates a SAML connection', async () => {
+      const mockSamlConnectionResponse = {
+        object: 'saml_connection',
+        id: 'samlc_123',
+        name: 'Test Connection',
+        provider: 'saml_custom',
+        domain: 'test.example.com',
+        organization_id: 'org_123',
+        created_at: 1672531200000,
+        updated_at: 1672531200000,
+        active: true,
+        sync_user_attributes: false,
+        allow_subdomains: false,
+        allow_idp_initiated: false,
+        idp_entity_id: 'entity_123',
+        idp_sso_url: 'https://idp.example.com/sso',
+        idp_certificate: 'cert_data',
+        idp_metadata_url: null,
+        idp_metadata: null,
+        attribute_mapping: {
+          user_id: 'userId',
+          email_address: 'email',
+          first_name: 'firstName',
+          last_name: 'lastName',
+        },
+      };
+
+      server.use(
+        http.patch(
+          'https://api.clerk.test/v1/saml_connections/samlc_123',
+          validateHeaders(async ({ request }) => {
+            const body = await request.json();
+
+            expect(body).toEqual({
+              name: 'Test Connection',
+              provider: 'saml_custom',
+              domain: 'test.example.com',
+              organization_id: 'org_123',
+              idp_entity_id: 'entity_123',
+              idp_sso_url: 'https://idp.example.com/sso',
+              idp_certificate: 'cert_data',
+              attribute_mapping: {
+                user_id: 'userId',
+                email_address: 'email',
+                first_name: 'firstName',
+                last_name: 'lastName',
+              },
+            });
+            return HttpResponse.json(mockSamlConnectionResponse);
+          }),
+        ),
+      );
+
+      const response = await apiClient.samlConnections.updateSamlConnection('samlc_123', {
+        name: 'Test Connection',
+        provider: 'saml_custom',
+        domain: 'test.example.com',
+        organizationId: 'org_123',
+        idpEntityId: 'entity_123',
+        idpSsoUrl: 'https://idp.example.com/sso',
+        idpCertificate: 'cert_data',
+        attributeMapping: {
+          user_id: 'userId',
+          email_address: 'email',
+          first_name: 'firstName',
+          last_name: 'lastName',
+        },
+      });
+
+      expect(response.id).toBe('samlc_123');
+      expect(response.name).toBe('Test Connection');
+      expect(response.organizationId).toBe('org_123');
+    });
+  });
 });
diff --git a/packages/backend/src/api/endpoints/SamlConnectionApi.ts b/packages/backend/src/api/endpoints/SamlConnectionApi.ts
index b800b344667..c5a39b30f1a 100644
--- a/packages/backend/src/api/endpoints/SamlConnectionApi.ts
+++ b/packages/backend/src/api/endpoints/SamlConnectionApi.ts
@@ -39,10 +39,10 @@ type CreateSamlConnectionParams = {
   idpMetadataUrl?: string;
   idpMetadata?: string;
   attributeMapping?: {
-    emailAddress?: string;
-    firstName?: string;
-    lastName?: string;
-    userId?: string;
+    email_address?: string;
+    first_name?: string;
+    last_name?: string;
+    user_id?: string;
   };
 };
 
@@ -57,10 +57,10 @@ type UpdateSamlConnectionParams = {
   idpMetadataUrl?: string;
   idpMetadata?: string;
   attributeMapping?: {
-    emailAddress?: string;
-    firstName?: string;
-    lastName?: string;
-    userId?: string;
+    email_address?: string;
+    first_name?: string;
+    last_name?: string;
+    user_id?: string;
   };
   active?: boolean;
   syncUserAttributes?: boolean;
@@ -102,6 +102,7 @@ export class SamlConnectionAPI extends AbstractAPI {
       bodyParams: params,
     });
   }
+
   public async deleteSamlConnection(samlConnectionId: string) {
     this.requireId(samlConnectionId);
     return this.request<SamlConnection>({