diff --git a/packages/eslint-plugin/src/rules/no-magic-numbers.ts b/packages/eslint-plugin/src/rules/no-magic-numbers.ts
index 772eaf49ea1..2bab38f752d 100644
--- a/packages/eslint-plugin/src/rules/no-magic-numbers.ts
+++ b/packages/eslint-plugin/src/rules/no-magic-numbers.ts
@@ -69,7 +69,7 @@ export default util.createRule<Options, MessageIds>({
 
         // Check if the node is a readonly class property
         if (
-          typeof node.value === 'number' &&
+          (typeof node.value === 'number' || typeof node.value === 'bigint') &&
           isParentTSReadonlyPropertyDefinition(node)
         ) {
           if (options.ignoreReadonlyClassProperties) {
diff --git a/packages/eslint-plugin/tests/rules/no-magic-numbers.test.ts b/packages/eslint-plugin/tests/rules/no-magic-numbers.test.ts
index 0c220805085..2bf16e99796 100644
--- a/packages/eslint-plugin/tests/rules/no-magic-numbers.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-magic-numbers.test.ts
@@ -53,6 +53,7 @@ class Foo {
   static readonly D = 1;
   readonly E = -1;
   readonly F = +1;
+  private readonly G = 100n;
 }
       `,
       options: [{ ignoreReadonlyClassProperties: true }],
@@ -204,6 +205,7 @@ class Foo {
   static readonly D = 4;
   readonly E = -5;
   readonly F = +6;
+  private readonly G = 100n;
 }
       `,
       options: [{ ignoreReadonlyClassProperties: false }],
@@ -256,6 +258,14 @@ class Foo {
           line: 8,
           column: 17,
         },
+        {
+          messageId: 'noMagic',
+          data: {
+            raw: '100n',
+          },
+          line: 9,
+          column: 24,
+        },
       ],
     },
   ],