diff --git a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
index c1b86bf8c61..bd48718c68b 100644
--- a/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
+++ b/packages/eslint-plugin/src/rules/consistent-indexed-object-style.ts
@@ -101,10 +101,10 @@ export default createRule<Options, MessageIds>({
         fix(fixer) {
           const key = sourceCode.getText(keyType.typeAnnotation);
           const value = sourceCode.getText(valueType.typeAnnotation);
-          return fixer.replaceText(
-            node,
-            `${prefix}Record<${key}, ${value}>${postfix}`,
-          );
+          const record = member.readonly
+            ? `Readonly<Record<${key}, ${value}>>`
+            : `Record<${key}, ${value}>`;
+          return fixer.replaceText(node, `${prefix}${record}${postfix}`);
         },
       });
     }
diff --git a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
index ebedccf424a..31077fcf620 100644
--- a/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
+++ b/packages/eslint-plugin/tests/rules/consistent-indexed-object-style.test.ts
@@ -140,6 +140,19 @@ type Foo = Record<string, any>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface
+    {
+      code: `
+interface Foo {
+  readonly [key: string]: any;
+}
+      `,
+      output: `
+type Foo = Readonly<Record<string, any>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Interface with generic parameter
     {
       code: `
@@ -153,6 +166,19 @@ type Foo<A> = Record<string, A>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface with generic parameter
+    {
+      code: `
+interface Foo<A> {
+  readonly [key: string]: A;
+}
+      `,
+      output: `
+type Foo<A> = Readonly<Record<string, A>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Interface with multiple generic parameters
     {
       code: `
@@ -166,6 +192,19 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
     },
 
+    // Readonly interface with multiple generic parameters
+    {
+      code: `
+interface Foo<A, B> {
+  readonly [key: A]: B;
+}
+      `,
+      output: `
+type Foo<A, B> = Readonly<Record<A, B>>;
+      `,
+      errors: [{ messageId: 'preferRecord', line: 2, column: 1 }],
+    },
+
     // Type literal
     {
       code: 'type Foo = { [key: string]: any };',
@@ -173,6 +212,13 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 12 }],
     },
 
+    // Readonly type literal
+    {
+      code: 'type Foo = { readonly [key: string]: any };',
+      output: 'type Foo = Readonly<Record<string, any>>;',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 12 }],
+    },
+
     // Generic
     {
       code: 'type Foo = Generic<{ [key: string]: any }>;',
@@ -180,6 +226,13 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 20 }],
     },
 
+    // Readonly Generic
+    {
+      code: 'type Foo = Generic<{ readonly [key: string]: any }>;',
+      output: 'type Foo = Generic<Readonly<Record<string, any>>>;',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 20 }],
+    },
+
     // Function types
     {
       code: 'function foo(arg: { [key: string]: any }) {}',
@@ -192,6 +245,18 @@ type Foo<A, B> = Record<A, B>;
       errors: [{ messageId: 'preferRecord', line: 1, column: 17 }],
     },
 
+    // Readonly function types
+    {
+      code: 'function foo(arg: { readonly [key: string]: any }) {}',
+      output: 'function foo(arg: Readonly<Record<string, any>>) {}',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 19 }],
+    },
+    {
+      code: 'function foo(): { readonly [key: string]: any } {}',
+      output: 'function foo(): Readonly<Record<string, any>> {}',
+      errors: [{ messageId: 'preferRecord', line: 1, column: 17 }],
+    },
+
     // Never
     // Type literal
     {