diff --git a/doc/api/deprecations.md b/doc/api/deprecations.md
index e71db997dc9a4f..48d018fc6df310 100644
--- a/doc/api/deprecations.md
+++ b/doc/api/deprecations.md
@@ -1077,6 +1077,9 @@ The `util.isDate()` API has been removed. Please use
 
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52744
+    description: End-of-Life deprecation.
   - version: v22.0.0
     pr-url: https://github.com/nodejs/node/pull/50488
     description: Runtime deprecation.
@@ -1092,9 +1095,9 @@ changes:
     description: Documentation-only deprecation.
 -->
 
-Type: Runtime
+Type: End-of-Life
 
-The [`util.isError()`][] API is deprecated. Please use
+The `util.isError()` API has been removed. Please use
 `Object.prototype.toString(arg) === '[object Error]' || arg instanceof Error`
 instead.
 
@@ -3809,8 +3812,6 @@ is deprecated to better align with recommendations per [NIST SP 800-38D][].
 [`util.inspect()`]: util.md#utilinspectobject-options
 [`util.inspect.custom`]: util.md#utilinspectcustom
 [`util.isArray()`]: util.md#utilisarrayobject
-[`util.isError()`]: util.md#utiliserrorobject
-[`util.isFunction()`]: util.md#utilisfunctionobject
 [`util.isPrimitive()`]: util.md#utilisprimitiveobject
 [`util.log()`]: util.md#utillogstring
 [`util.promisify`]: util.md#utilpromisifyoriginal
diff --git a/doc/api/util.md b/doc/api/util.md
index 2da1963e59069b..2635a60d878bc3 100644
--- a/doc/api/util.md
+++ b/doc/api/util.md
@@ -2950,47 +2950,6 @@ util.isArray({});
 // Returns: false
 ```
 
-### `util.isError(object)`
-
-<!-- YAML
-added: v0.6.0
-deprecated: v4.0.0
--->
-
-> Stability: 0 - Deprecated: Use [`util.types.isNativeError()`][] instead.
-
-* `object` {any}
-* Returns: {boolean}
-
-Returns `true` if the given `object` is an [`Error`][]. Otherwise, returns
-`false`.
-
-```js
-const util = require('node:util');
-
-util.isError(new Error());
-// Returns: true
-util.isError(new TypeError());
-// Returns: true
-util.isError({ name: 'Error', message: 'an error occurred' });
-// Returns: false
-```
-
-This method relies on `Object.prototype.toString()` behavior. It is
-possible to obtain an incorrect result when the `object` argument manipulates
-`@@toStringTag`.
-
-```js
-const util = require('node:util');
-const obj = { name: 'Error', message: 'an error occurred' };
-
-util.isError(obj);
-// Returns: false
-obj[Symbol.toStringTag] = 'Error';
-util.isError(obj);
-// Returns: true
-```
-
 ### `util.isFunction(object)`
 
 <!-- YAML
@@ -3094,7 +3053,6 @@ util.log('Timestamped message.');
 [`ArrayBuffer`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer
 [`DataView`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView
 [`Date`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
-[`Error`]: errors.md#class-error
 [`Float32Array`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array
 [`Float64Array`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float64Array
 [`Int16Array`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int16Array
@@ -3127,7 +3085,6 @@ util.log('Timestamped message.');
 [`util.promisify()`]: #utilpromisifyoriginal
 [`util.types.isAnyArrayBuffer()`]: #utiltypesisanyarraybuffervalue
 [`util.types.isArrayBuffer()`]: #utiltypesisarraybuffervalue
-[`util.types.isNativeError()`]: #utiltypesisnativeerrorvalue
 [`util.types.isSharedArrayBuffer()`]: #utiltypesissharedarraybuffervalue
 [async function]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function
 [built-in `Error` type]: https://tc39.es/ecma262/#sec-error-objects
diff --git a/lib/util.js b/lib/util.js
index 7114c24ad26d7d..118415509e0d86 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -39,7 +39,6 @@ const {
   ObjectDefineProperty,
   ObjectGetOwnPropertyDescriptors,
   ObjectKeys,
-  ObjectPrototypeToString,
   ObjectSetPrototypeOf,
   ObjectValues,
   ReflectApply,
@@ -90,15 +89,6 @@ function lazyAbortController() {
 
 let internalDeepEqual;
 
-/**
- * @deprecated since v4.0.0
- * @param {any} e
- * @returns {arg is Error}
- */
-function isError(e) {
-  return ObjectPrototypeToString(e) === '[object Error]' || e instanceof Error;
-}
-
 /**
  * @deprecated since v4.0.0
  * @param {any} arg
@@ -354,11 +344,6 @@ module.exports = {
     }
     return internalDeepEqual(a, b);
   },
-  isError: deprecate(isError,
-                     'The `util.isError` API is deprecated. ' +
-                     'Please use `ObjectPrototypeToString(e) === "[object Error]" ' +
-                     '|| e instanceof Error` instead.',
-                     'DEP0048'),
   isFunction: deprecate(isFunction,
                         'The `util.isFunction` API is deprecated.  Please use `typeof arg === "function"` instead.',
                         'DEP0049'),
diff --git a/test/parallel/test-util.js b/test/parallel/test-util.js
index c509a52967eb8c..ff3b033610b40c 100644
--- a/test/parallel/test-util.js
+++ b/test/parallel/test-util.js
@@ -40,18 +40,6 @@ assert.strictEqual(util.isArray(/regexp/), false);
 assert.strictEqual(util.isArray(new Error()), false);
 assert.strictEqual(util.isArray({ __proto__: Array.prototype }), false);
 
-// isError
-assert.strictEqual(util.isError(new Error()), true);
-assert.strictEqual(util.isError(new TypeError()), true);
-assert.strictEqual(util.isError(new SyntaxError()), true);
-assert.strictEqual(util.isError(new (context('Error'))()), true);
-assert.strictEqual(util.isError(new (context('TypeError'))()), true);
-assert.strictEqual(util.isError(new (context('SyntaxError'))()), true);
-assert.strictEqual(util.isError({}), false);
-assert.strictEqual(util.isError({ name: 'Error', message: '' }), false);
-assert.strictEqual(util.isError([]), false);
-assert.strictEqual(util.isError({ __proto__: Error.prototype }), true);
-
 // isPrimitive
 assert.strictEqual(util.isPrimitive({}), false);
 assert.strictEqual(util.isPrimitive(new Error()), false);
@@ -62,8 +50,6 @@ assert.strictEqual(util.isPrimitive(function() {}), false);
 assert.strictEqual(util.isPrimitive(new Number(1)), false);
 assert.strictEqual(util.isPrimitive(new String('bla')), false);
 assert.strictEqual(util.isPrimitive(new Boolean(true)), false);
-assert.strictEqual(util.isPrimitive(1), true);
-assert.strictEqual(util.isPrimitive('bla'), true);
 assert.strictEqual(util.isPrimitive(true), true);
 assert.strictEqual(util.isPrimitive(undefined), true);
 assert.strictEqual(util.isPrimitive(null), true);