diff --git a/packages/browser-utils/src/metrics/webVitalSpans.ts b/packages/browser-utils/src/metrics/webVitalSpans.ts
index 9c4f82249874..89024148865c 100644
--- a/packages/browser-utils/src/metrics/webVitalSpans.ts
+++ b/packages/browser-utils/src/metrics/webVitalSpans.ts
@@ -1,6 +1,7 @@
 import type { Client, Integration, Span, SpanAttributes } from '@sentry/core';
 import {
   browserPerformanceTimeOrigin,
+  correctedPerformanceTimeOrigin,
   debug,
   getActiveSpan,
   getClient,
@@ -329,7 +330,9 @@ export function trackInpAsSpan(client: Client): void {
 export function _sendInpSpan(inpValue: number, entry: PerformanceEventTiming, standalone = false): void {
   DEBUG_BUILD && debug.log(`Sending INP span (${inpValue})`);
 
-  const startTime = msToSec((browserPerformanceTimeOrigin() as number) + entry.startTime);
+  // INP reports on pagehide, potentially hours after the origin cached at init, so the corrected origin is used to stay
+  // on the same timeline as span and event timestamps.
+  const startTime = msToSec((correctedPerformanceTimeOrigin() as number) + entry.startTime);
   const duration = msToSec(inpValue);
   const interactionType = INP_ENTRY_MAP[entry.name];
 
diff --git a/packages/browser-utils/test/metrics/webVitalSpans.test.ts b/packages/browser-utils/test/metrics/webVitalSpans.test.ts
index ef938d7017f0..95fc1494447e 100644
--- a/packages/browser-utils/test/metrics/webVitalSpans.test.ts
+++ b/packages/browser-utils/test/metrics/webVitalSpans.test.ts
@@ -17,6 +17,7 @@ vi.mock('@sentry/core', async () => {
   return {
     ...actual,
     browserPerformanceTimeOrigin: vi.fn(),
+    correctedPerformanceTimeOrigin: vi.fn(),
     timestampInSeconds: vi.fn(),
     getCurrentScope: vi.fn(),
     getClient: vi.fn(),
@@ -475,6 +476,7 @@ describe('_sendInpSpan', () => {
   beforeEach(() => {
     vi.mocked(SentryCore.getCurrentScope).mockReturnValue(mockScope as any);
     vi.mocked(SentryCore.browserPerformanceTimeOrigin).mockReturnValue(1000);
+    vi.mocked(SentryCore.correctedPerformanceTimeOrigin).mockReturnValue(1000);
     vi.mocked(htmlTreeAsString).mockReturnValue('<button>');
     vi.mocked(SentryCore.startInactiveSpan).mockReturnValue(mockSpan as any);
     vi.mocked(SentryCore.getActiveSpan).mockReturnValue(undefined);
@@ -592,6 +594,7 @@ describe('trackInpAsSpan', () => {
 
   beforeEach(() => {
     vi.mocked(SentryCore.browserPerformanceTimeOrigin).mockReturnValue(1000);
+    vi.mocked(SentryCore.correctedPerformanceTimeOrigin).mockReturnValue(1000);
     vi.mocked(SentryCore.getCurrentScope).mockReturnValue(mockScope as any);
     vi.mocked(SentryCore.getActiveSpan).mockReturnValue(undefined);
     vi.mocked(SentryCore.startInactiveSpan).mockReturnValue({ end: vi.fn() } as any);
diff --git a/packages/browser/src/profiling/utils.ts b/packages/browser/src/profiling/utils.ts
index 938b7eadb784..d8be3d17f9db 100644
--- a/packages/browser/src/profiling/utils.ts
+++ b/packages/browser/src/profiling/utils.ts
@@ -12,7 +12,7 @@ import type {
   ThreadCpuProfile,
 } from '@sentry/core/browser';
 import {
-  browserPerformanceTimeOrigin,
+  correctedPerformanceTimeOrigin,
   debug,
   DEFAULT_ENVIRONMENT,
   forEachEnvelopeItem,
@@ -339,7 +339,7 @@ function convertToContinuousProfile(input: {
   }
 
   // Align timestamps to SDK time origin to match span/event timelines
-  const perfOrigin = browserPerformanceTimeOrigin();
+  const perfOrigin = correctedPerformanceTimeOrigin();
   const origin = typeof performance.timeOrigin === 'number' ? performance.timeOrigin : perfOrigin || 0;
   const adjustForOriginChange = origin - (perfOrigin || origin);
 
@@ -412,7 +412,7 @@ export function convertJSSelfProfileToSampledFormat(input: JSSelfProfile): Profi
   // when that happens, we need to ensure we are correcting the profile timings so the two timelines stay in sync.
   // Since JS self profiling time origin is always initialized to performance.timeOrigin, we need to adjust for
   // the drift between the SDK selected value and our profile time origin.
-  const perfOrigin = browserPerformanceTimeOrigin();
+  const perfOrigin = correctedPerformanceTimeOrigin();
   const origin = typeof performance.timeOrigin === 'number' ? performance.timeOrigin : perfOrigin || 0;
   const adjustForOriginChange = origin - (perfOrigin || origin);
 
diff --git a/packages/core/src/shared-exports.ts b/packages/core/src/shared-exports.ts
index 057d70a37e47..c63283b4203d 100644
--- a/packages/core/src/shared-exports.ts
+++ b/packages/core/src/shared-exports.ts
@@ -274,7 +274,12 @@ export {
   supportsReferrerPolicy,
 } from './utils/supports';
 export { SyncPromise, rejectedSyncPromise, resolvedSyncPromise } from './utils/syncpromise';
-export { browserPerformanceTimeOrigin, dateTimestampInSeconds, timestampInSeconds } from './utils/time';
+export {
+  browserPerformanceTimeOrigin,
+  correctedPerformanceTimeOrigin,
+  dateTimestampInSeconds,
+  timestampInSeconds,
+} from './utils/time';
 export {
   TRACEPARENT_REGEXP,
   extractTraceparentData,
diff --git a/packages/core/src/utils/time.ts b/packages/core/src/utils/time.ts
index 00283bc6e48f..9f841ef6f2c9 100644
--- a/packages/core/src/utils/time.ts
+++ b/packages/core/src/utils/time.ts
@@ -31,6 +31,12 @@ export function dateTimestampInSeconds(): number {
   return safeDateNow() / ONE_SECOND_IN_MS;
 }
 
+/**
+ * The time origin `timestampInSeconds` currently maps the monotonic clock against, kept in sync with the corrections it
+ * applies. `undefined` until the first `timestampInSeconds` call, and whenever the Performance API is unavailable.
+ */
+let _correctedTimeOrigin: number | undefined;
+
 /**
  * Returns a wrapper around the native Performance API browser implementation, or undefined for browsers that do not
  * support the API.
@@ -47,7 +53,7 @@ function createUnixTimestampInSecondsFunc(): () => number {
 
   // performance.now() is a monotonic clock, which means it starts at 0 when the process begins. To get the current
   // wall clock time (actual UNIX timestamp), we need to add the starting time origin and the current time elapsed.
-  let timeOrigin = performance.timeOrigin;
+  let timeOrigin = (_correctedTimeOrigin = performance.timeOrigin);
 
   return () => {
     return withRandomSafeContext(() => {
@@ -66,7 +72,7 @@ function createUnixTimestampInSecondsFunc(): () => number {
       // See: https://github.com/mdn/content/issues/4713
       // See: https://dev.to/noamr/when-a-millisecond-is-not-a-millisecond-3h6
       if (Math.abs(timeOrigin + performanceNow - dateNow) > CLOCK_DRIFT_THRESHOLD_MS) {
-        timeOrigin = dateNow - performanceNow;
+        timeOrigin = _correctedTimeOrigin = dateNow - performanceNow;
       }
 
       return (timeOrigin + performanceNow) / ONE_SECOND_IN_MS;
@@ -76,6 +82,20 @@ function createUnixTimestampInSecondsFunc(): () => number {
 
 let _cachedTimestampInSeconds: (() => number) | undefined;
 
+/**
+ * Returns the time origin (in milliseconds since the UNIX epoch) that {@link timestampInSeconds} currently maps
+ * `performance.now()` against, including any correction it has applied for clock drift.
+ *
+ * Use this over {@link browserPerformanceTimeOrigin} when converting a `PerformanceEntry`'s monotonic `startTime` to
+ * wall clock time at the moment the entry is observed, so the result shares a timeline with span and event timestamps.
+ * Returns `undefined` if the Performance API is unavailable, in which case monotonic timestamps cannot be converted.
+ */
+export function correctedPerformanceTimeOrigin(): number | undefined {
+  // The origin is only populated once `timestampInSeconds` has resolved which clock source to use.
+  timestampInSeconds();
+  return _correctedTimeOrigin;
+}
+
 /**
  * Returns a timestamp in seconds since the UNIX epoch using either the Performance or Date APIs, depending on the
  * availability of the Performance API.
diff --git a/packages/core/test/lib/utils/time.test.ts b/packages/core/test/lib/utils/time.test.ts
index 70fc7e5c0243..20cd71dd22ae 100644
--- a/packages/core/test/lib/utils/time.test.ts
+++ b/packages/core/test/lib/utils/time.test.ts
@@ -9,11 +9,17 @@ async function getFreshPerformanceTimeOrigin() {
 
 let freshImportCounter = 0;
 
-async function getFreshTimestampInSeconds(): Promise<() => number> {
+async function getFreshTimeModule(): Promise<{
+  timestampInSeconds: () => number;
+  correctedPerformanceTimeOrigin: () => number | undefined;
+}> {
   // A counter rather than `Date.now()`: these tests run under fake timers, which freeze the wall clock and would
   // otherwise hand out a cached module.
-  const timeModule = await import(`../../../src/utils/time?update=${freshImportCounter++}`);
-  return timeModule.timestampInSeconds;
+  return import(`../../../src/utils/time?update=${freshImportCounter++}`);
+}
+
+async function getFreshTimestampInSeconds(): Promise<() => number> {
+  return (await getFreshTimeModule()).timestampInSeconds;
 }
 
 const RELIABLE_THRESHOLD_MS = 300_000;
@@ -180,6 +186,75 @@ describe('timestampInSeconds', () => {
   });
 });
 
+describe('correctedPerformanceTimeOrigin', () => {
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.unstubAllGlobals();
+  });
+
+  it('returns `performance.timeOrigin` while the clocks agree', async () => {
+    const currentTimeMs = 1767778040866;
+    const timeSincePageloadMs = 1_000;
+    const timeOrigin = currentTimeMs - timeSincePageloadMs;
+
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(currentTimeMs));
+    vi.stubGlobal('performance', { timeOrigin, now: () => timeSincePageloadMs });
+
+    const { correctedPerformanceTimeOrigin } = await getFreshTimeModule();
+
+    expect(correctedPerformanceTimeOrigin()).toBe(timeOrigin);
+  });
+
+  it('returns the corrected origin after clock drift, without a prior `timestampInSeconds` call', async () => {
+    const currentTimeMs = 1767778040866;
+    const timeSincePageloadMs = 1_000;
+    const sleepDurationMs = RELIABLE_THRESHOLD_MS + 60_000;
+
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(currentTimeMs));
+    vi.stubGlobal('performance', {
+      timeOrigin: currentTimeMs - timeSincePageloadMs,
+      now: () => timeSincePageloadMs,
+    });
+
+    const { correctedPerformanceTimeOrigin } = await getFreshTimeModule();
+
+    vi.setSystemTime(new Date(currentTimeMs + sleepDurationMs));
+
+    expect(correctedPerformanceTimeOrigin()).toBe(currentTimeMs + sleepDurationMs - timeSincePageloadMs);
+  });
+
+  it('stays on the same timeline as `timestampInSeconds`', async () => {
+    const currentTimeMs = 1767778040866;
+    const timeSincePageloadMs = 1_000;
+    const sleepDurationMs = RELIABLE_THRESHOLD_MS + 60_000;
+
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(currentTimeMs));
+    vi.stubGlobal('performance', {
+      timeOrigin: currentTimeMs - timeSincePageloadMs,
+      now: () => timeSincePageloadMs,
+    });
+
+    const { correctedPerformanceTimeOrigin, timestampInSeconds } = await getFreshTimeModule();
+
+    vi.setSystemTime(new Date(currentTimeMs + sleepDurationMs));
+
+    // Converting the current `performance.now()` against the origin must yield the same wall clock time that
+    // `timestampInSeconds` reports, otherwise perf entries and spans land on diverging timelines.
+    expect((correctedPerformanceTimeOrigin() as number) + timeSincePageloadMs).toBe(timestampInSeconds() * 1000);
+  });
+
+  it('returns `undefined` if the performance API is unavailable', async () => {
+    vi.stubGlobal('performance', undefined);
+
+    const { correctedPerformanceTimeOrigin } = await getFreshTimeModule();
+
+    expect(correctedPerformanceTimeOrigin()).toBeUndefined();
+  });
+});
+
 describe('browserPerformanceTimeOrigin', () => {
   it('returns `performance.timeOrigin` if it is available and reliable', async () => {
     const timeOrigin = await getFreshPerformanceTimeOrigin();
diff --git a/packages/replay-internal/src/util/createPerformanceEntries.ts b/packages/replay-internal/src/util/createPerformanceEntries.ts
index 5d3435b7efbc..2f4e45e9b600 100644
--- a/packages/replay-internal/src/util/createPerformanceEntries.ts
+++ b/packages/replay-internal/src/util/createPerformanceEntries.ts
@@ -1,4 +1,4 @@
-import { browserPerformanceTimeOrigin } from '@sentry/core';
+import { correctedPerformanceTimeOrigin } from '@sentry/core';
 import { record } from '@sentry/rrweb';
 import { WINDOW } from '../constants';
 import type {
@@ -87,9 +87,9 @@ function createPerformanceEntry(entry: AllPerformanceEntry): ReplayPerformanceEn
 }
 
 function getAbsoluteTime(time: number): number {
-  // browserPerformanceTimeOrigin can be undefined if `performance` or
+  // correctedPerformanceTimeOrigin can be undefined if `performance` or
   // `performance.now` doesn't exist, but this is already checked by this integration
-  return ((browserPerformanceTimeOrigin() || WINDOW.performance.timeOrigin) + time) / 1000;
+  return ((correctedPerformanceTimeOrigin() || WINDOW.performance.timeOrigin) + time) / 1000;
 }
 
 function createPaintEntry(entry: PerformancePaintTiming): ReplayPerformanceEntry<PaintData> {