diff --git a/.changeset/soft-scissors-turn.md b/.changeset/soft-scissors-turn.md
new file mode 100644
index 0000000000..fd0c3f1f12
--- /dev/null
+++ b/.changeset/soft-scissors-turn.md
@@ -0,0 +1,5 @@
+---
+"@guardian/cdk": minor
+---
+
+Default to GP3 storage type for RDS
diff --git a/src/constructs/rds/instance.test.ts b/src/constructs/rds/instance.test.ts
index f78bb2ad9f..546af11001 100644
--- a/src/constructs/rds/instance.test.ts
+++ b/src/constructs/rds/instance.test.ts
@@ -1,7 +1,7 @@
 import { Duration, Stack } from "aws-cdk-lib";
 import { Match, Template } from "aws-cdk-lib/assertions";
 import { Vpc } from "aws-cdk-lib/aws-ec2";
-import { DatabaseInstanceEngine, PostgresEngineVersion } from "aws-cdk-lib/aws-rds";
+import { DatabaseInstanceEngine, PostgresEngineVersion, StorageType } from "aws-cdk-lib/aws-rds";
 import { GuTemplate, simpleGuStackForTesting } from "../../utils/test";
 import { GuDatabaseInstance } from "./instance";
 
@@ -147,4 +147,41 @@ describe("The GuDatabaseInstance class", () => {
       PreferredBackupWindow: "00:00-02:00",
     });
   });
+
+  test("defaults to GP3 storage type", () => {
+    const stack = simpleGuStackForTesting();
+    new GuDatabaseInstance(stack, "DatabaseInstance", {
+      vpc,
+      instanceType: "t3.small",
+      engine: DatabaseInstanceEngine.postgres({
+        version: PostgresEngineVersion.VER_16,
+      }),
+      app: "testing",
+      devXBackups: {
+        enabled: true,
+      },
+    });
+    Template.fromStack(stack).hasResourceProperties("AWS::RDS::DBInstance", {
+      StorageType: "gp3",
+    });
+  });
+
+  test("uses the specified storage type when the default is overridden", () => {
+    const stack = simpleGuStackForTesting();
+    new GuDatabaseInstance(stack, "DatabaseInstance", {
+      vpc,
+      instanceType: "t3.small",
+      engine: DatabaseInstanceEngine.postgres({
+        version: PostgresEngineVersion.VER_16,
+      }),
+      app: "testing",
+      devXBackups: {
+        enabled: true,
+      },
+      storageType: StorageType.GP2, // ← Overriding default storage type here
+    });
+    Template.fromStack(stack).hasResourceProperties("AWS::RDS::DBInstance", {
+      StorageType: "gp2",
+    });
+  });
 });
diff --git a/src/constructs/rds/instance.ts b/src/constructs/rds/instance.ts
index 69a2ba8e08..c9011f53e2 100644
--- a/src/constructs/rds/instance.ts
+++ b/src/constructs/rds/instance.ts
@@ -1,6 +1,6 @@
 import { Fn, Tags } from "aws-cdk-lib";
 import { InstanceType } from "aws-cdk-lib/aws-ec2";
-import { DatabaseInstance } from "aws-cdk-lib/aws-rds";
+import { DatabaseInstance, StorageType } from "aws-cdk-lib/aws-rds";
 import type { DatabaseInstanceProps } from "aws-cdk-lib/aws-rds";
 import { GuAppAwareConstruct } from "../../utils/mixin/app-aware-construct";
 import type { AppIdentity, GuStack } from "../core";
@@ -39,6 +39,7 @@ export class GuDatabaseInstance extends GuAppAwareConstruct(DatabaseInstance) {
     const instanceType = new InstanceType(Fn.join("", Fn.split("db.", props.instanceType)));
 
     super(scope, id, {
+      storageType: StorageType.GP3,
       deletionProtection: true,
       deleteAutomatedBackups: false,
       backupRetention: props.devXBackups.enabled ? undefined : props.devXBackups.backupRetention,