diff --git a/Libraries/WebPerformance/NativePerformanceObserver.cpp b/Libraries/WebPerformance/NativePerformanceObserver.cpp
index 32ab293e6cbf37..21bfd9feafb4e3 100644
--- a/Libraries/WebPerformance/NativePerformanceObserver.cpp
+++ b/Libraries/WebPerformance/NativePerformanceObserver.cpp
@@ -39,4 +39,13 @@ void NativePerformanceObserver::setOnPerformanceEntryCallback(
             << (callback ? "non-empty" : "empty");
 }
 
+void NativePerformanceObserver::logEntryForDebug(
+    jsi::Runtime &rt,
+    RawPerformanceEntry entry) {
+  LOG(INFO) << "NativePerformanceObserver::logEntry: "
+            << "name=" << entry.name << " type=" << entry.entryType
+            << " startTime=" << entry.startTime
+            << " duration=" << entry.duration;
+}
+
 } // namespace facebook::react
diff --git a/Libraries/WebPerformance/NativePerformanceObserver.h b/Libraries/WebPerformance/NativePerformanceObserver.h
index 3a3250dcbcc6e7..e001370f1e26dd 100644
--- a/Libraries/WebPerformance/NativePerformanceObserver.h
+++ b/Libraries/WebPerformance/NativePerformanceObserver.h
@@ -57,6 +57,8 @@ class NativePerformanceObserver
       jsi::Runtime &rt,
       std::optional<AsyncCallback<>> callback);
 
+  void logEntryForDebug(jsi::Runtime &rt, RawPerformanceEntry entry);
+
  private:
   std::optional<AsyncCallback<>> callback_;
 };
diff --git a/Libraries/WebPerformance/NativePerformanceObserver.js b/Libraries/WebPerformance/NativePerformanceObserver.js
index b3d6fdefc8b7f7..c74502eb80a31a 100644
--- a/Libraries/WebPerformance/NativePerformanceObserver.js
+++ b/Libraries/WebPerformance/NativePerformanceObserver.js
@@ -14,6 +14,7 @@ import * as TurboModuleRegistry from '../TurboModule/TurboModuleRegistry';
 
 export const RawPerformanceEntryTypeValues = {
   UNDEFINED: 0,
+  MARK: 1,
 };
 
 export type RawPerformanceEntryType = number;
@@ -34,6 +35,9 @@ export interface Spec extends TurboModule {
   +stopReporting: (entryType: string) => void;
   +getPendingEntries: () => $ReadOnlyArray<RawPerformanceEntry>;
   +setOnPerformanceEntryCallback: (callback?: () => void) => void;
+
+  // NOTE: this is for dev-only purposes (potentially is going to be moved elsewhere)
+  +logEntryForDebug?: (entry: RawPerformanceEntry) => void;
 }
 
 export default (TurboModuleRegistry.get<Spec>(
diff --git a/Libraries/WebPerformance/Performance.js b/Libraries/WebPerformance/Performance.js
new file mode 100644
index 00000000000000..5b1de3ea225e25
--- /dev/null
+++ b/Libraries/WebPerformance/Performance.js
@@ -0,0 +1,66 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow strict
+ */
+
+import type {HighResTimeStamp} from './PerformanceObserver';
+
+import NativePerformanceObserver, {
+  RawPerformanceEntryTypeValues,
+} from './NativePerformanceObserver';
+import {PerformanceEntry} from './PerformanceObserver';
+
+type DetailType = mixed;
+
+export type PerformanceMarkOptions = {
+  detail?: DetailType,
+  startTime?: HighResTimeStamp,
+};
+
+function getCurrentTimeStamp(): HighResTimeStamp {
+  return global.nativePerformanceNow?.() ?? Date.now();
+}
+
+export class PerformanceMark extends PerformanceEntry {
+  detail: DetailType;
+
+  constructor(markName: string, markOptions?: PerformanceMarkOptions) {
+    let startTime = markOptions?.startTime ?? getCurrentTimeStamp();
+    super({name: markName, entryType: 'mark', startTime, duration: 0});
+    if (markOptions !== undefined) {
+      this.detail = markOptions.detail;
+    }
+  }
+}
+
+/**
+ * Partial implementation of the Performance interface for RN,
+ * corresponding to the standard in
+ *  https://www.w3.org/TR/user-timing/#extensions-performance-interface
+ */
+export default class Performance {
+  mark(
+    markName: string,
+    markOptions?: PerformanceMarkOptions,
+  ): PerformanceMark {
+    const mark = new PerformanceMark(markName, markOptions);
+    NativePerformanceObserver?.logEntryForDebug?.({
+      name: markName,
+      entryType: RawPerformanceEntryTypeValues.MARK,
+      startTime: mark.startTime,
+      duration: mark.duration,
+    });
+    return mark;
+  }
+
+  clearMarks(markName?: string): void {}
+
+  now(): HighResTimeStamp {
+    return getCurrentTimeStamp();
+  }
+}
diff --git a/Libraries/WebPerformance/PerformanceObserver.js b/Libraries/WebPerformance/PerformanceObserver.js
index dc9a0c4aff6f47..b3cf01d9931798 100644
--- a/Libraries/WebPerformance/PerformanceObserver.js
+++ b/Libraries/WebPerformance/PerformanceObserver.js
@@ -18,8 +18,7 @@ import NativePerformanceObserver from './NativePerformanceObserver';
 
 export type HighResTimeStamp = number;
 // TODO: Extend once new types (such as event) are supported.
-// TODO: Get rid of the "undefined" once there is at least one type supported.
-export type PerformanceEntryType = 'undefined';
+export type PerformanceEntryType = 'undefined' | 'mark';
 
 export class PerformanceEntry {
   name: string;
@@ -53,7 +52,7 @@ export class PerformanceEntry {
 function rawToPerformanceEntryType(
   type: RawPerformanceEntryType,
 ): PerformanceEntryType {
-  return 'undefined';
+  return 'mark';
 }
 
 function rawToPerformanceEntry(entry: RawPerformanceEntry): PerformanceEntry {
@@ -166,7 +165,7 @@ export default class PerformanceObserver {
     } else {
       this._entryTypes = new Set([options.type]);
     }
-    this._entryTypes.forEach(type => {
+    for (const type of this._entryTypes) {
       if (!_observedEntryTypeRefCount.has(type)) {
         NativePerformanceObserver.startReporting(type);
       }
@@ -174,7 +173,7 @@ export default class PerformanceObserver {
         type,
         (_observedEntryTypeRefCount.get(type) ?? 0) + 1,
       );
-    });
+    }
     _observers.add(this);
   }
 
@@ -183,7 +182,7 @@ export default class PerformanceObserver {
       warnNoNativePerformanceObserver();
       return;
     }
-    this._entryTypes.forEach(type => {
+    for (const type of this._entryTypes) {
       const entryTypeRefCount = _observedEntryTypeRefCount.get(type) ?? 0;
       if (entryTypeRefCount === 1) {
         _observedEntryTypeRefCount.delete(type);
@@ -191,7 +190,7 @@ export default class PerformanceObserver {
       } else if (entryTypeRefCount !== 0) {
         _observedEntryTypeRefCount.set(type, entryTypeRefCount - 1);
       }
-    });
+    }
     _observers.delete(this);
     if (_observers.size === 0) {
       NativePerformanceObserver.setOnPerformanceEntryCallback(undefined);
@@ -201,7 +200,7 @@ export default class PerformanceObserver {
 
   static supportedEntryTypes: $ReadOnlyArray<PerformanceEntryType> =
     // TODO: add types once they are fully supported
-    Object.freeze([]);
+    Object.freeze(['mark']);
 }
 
 // This is a callback that gets scheduled and periodically called from the native side
@@ -211,7 +210,7 @@ function onPerformanceEntry() {
   }
   const rawEntries = NativePerformanceObserver.getPendingEntries();
   const entries = rawEntries.map(rawToPerformanceEntry);
-  _observers.forEach(observer => {
+  for (const observer of _observers) {
     const entriesForObserver: PerformanceEntryList = entries.filter(entry =>
       observer._entryTypes.has(entry.entryType),
     );
@@ -219,5 +218,5 @@ function onPerformanceEntry() {
       new PerformanceObserverEntryList(entriesForObserver),
       observer,
     );
-  });
+  }
 }