diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tests/InspectorPackagerConnectionTest.cpp b/packages/react-native/ReactCommon/jsinspector-modern/tests/InspectorPackagerConnectionTest.cpp
index e0ed7fcdacb..878f5356f30 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tests/InspectorPackagerConnectionTest.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tests/InspectorPackagerConnectionTest.cpp
@@ -16,6 +16,7 @@
 #include <jsinspector-modern/InspectorInterfaces.h>
 #include <jsinspector-modern/InspectorPackagerConnection.h>
 
+#include <format>
 #include <memory>
 
 #include "FollyDynamicMatchers.h"
@@ -25,7 +26,7 @@
 using namespace ::testing;
 using namespace std::literals::chrono_literals;
 using namespace std::literals::string_literals;
-using folly::dynamic, folly::toJson, folly::sformat;
+using folly::dynamic, folly::toJson;
 
 namespace facebook::react::jsinspector_modern {
 
@@ -281,7 +282,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendReceiveEvents) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -321,7 +322,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendReceiveEvents) {
           AtJsonPtr("/params", ElementsAre("arg1", "arg2"))))))
       .RetiresOnSaturation();
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -373,7 +374,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendReceiveEventsToMultiplePages) {
 
   for (int i = 0; i < kNumPages; ++i) {
     // Connect to the i-th page.
-    webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+    webSockets_[0]->getDelegate().didReceiveMessage(std::format(
         R"({{
         "event": "connect",
         "payload": {{
@@ -415,7 +416,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendReceiveEventsToMultiplePages) {
         *localConnections_[i],
         sendMessage(JsonParsed(AtJsonPtr("/method", Eq(method)))))
         .RetiresOnSaturation();
-    webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+    webSockets_[0]->getDelegate().didReceiveMessage(std::format(
         R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -445,7 +446,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendEventToAllConnections) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -486,7 +487,7 @@ TEST_F(InspectorPackagerConnectionTest, TestConnectThenDisconnect) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -498,7 +499,7 @@ TEST_F(InspectorPackagerConnectionTest, TestConnectThenDisconnect) {
 
   // Disconnect from the page.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -521,7 +522,7 @@ TEST_F(InspectorPackagerConnectionTest, TestConnectThenCloseSocket) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -549,7 +550,7 @@ TEST_F(InspectorPackagerConnectionTest, TestConnectThenSocketFailure) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -579,7 +580,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -625,7 +626,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -637,7 +638,7 @@ TEST_F(
 
   // Try connecting to the same page again. This results in a disconnection.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -660,7 +661,7 @@ TEST_F(InspectorPackagerConnectionTest, TestMultipleDisconnect) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -672,7 +673,7 @@ TEST_F(InspectorPackagerConnectionTest, TestMultipleDisconnect) {
 
   // Disconnect from the page.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -683,7 +684,7 @@ TEST_F(InspectorPackagerConnectionTest, TestMultipleDisconnect) {
   EXPECT_FALSE(localConnections_[0]);
 
   // Disconnect again. This is a noop.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -706,7 +707,7 @@ TEST_F(InspectorPackagerConnectionTest, TestDisconnectThenSendEvent) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -718,7 +719,7 @@ TEST_F(InspectorPackagerConnectionTest, TestDisconnectThenSendEvent) {
 
   // Disconnect from the page.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -730,7 +731,7 @@ TEST_F(InspectorPackagerConnectionTest, TestDisconnectThenSendEvent) {
 
   // Send an event from the frontend (remote) to the backend (local). This
   // is a noop.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -754,7 +755,7 @@ TEST_F(InspectorPackagerConnectionTest, TestSendEventToUnknownPage) {
 
   // Send an event from the frontend (remote) to the backend (local). This
   // is a noop (except for logging).
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -921,7 +922,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  retainedWebSocketDelegate->didReceiveMessage(sformat(
+  retainedWebSocketDelegate->didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -941,7 +942,7 @@ TEST_F(
           AtJsonPtr("/params", ElementsAre("arg1", "arg2"))))))
       .RetiresOnSaturation();
 
-  retainedWebSocketDelegate->didReceiveMessage(sformat(
+  retainedWebSocketDelegate->didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -975,7 +976,7 @@ TEST_F(InspectorPackagerConnectionTest, TestDestroyConnectionOnPageRemoved) {
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1005,7 +1006,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1045,7 +1046,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1064,7 +1065,7 @@ TEST_F(
 
   // Disconnect from the page.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -1075,7 +1076,7 @@ TEST_F(
   EXPECT_FALSE(localConnections_[0]);
 
   // Connect to the same page again.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1127,7 +1128,7 @@ TEST_F(
           .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
 
   // Connect to the page.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1151,7 +1152,7 @@ TEST_F(
 
   // Disconnect from the page.
   EXPECT_CALL(*localConnections_[0], disconnect()).RetiresOnSaturation();
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "disconnect",
           "payload": {{
@@ -1162,7 +1163,7 @@ TEST_F(
   EXPECT_FALSE(localConnections_[0]);
 
   // Connect to the same page again.
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1256,7 +1257,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
           AtJsonPtr("/payload/pageId", Eq(std::to_string(pageId)))))))
       .RetiresOnSaturation();
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1265,7 +1266,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
         }})",
       toJson(std::to_string(pageId))));
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -1291,7 +1292,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
           AtJsonPtr("/payload/pageId", Eq(std::to_string(pageId)))))))
       .RetiresOnSaturation();
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1300,7 +1301,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
         }})",
       toJson(std::to_string(pageId))));
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
@@ -1319,7 +1320,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
   // page.
   mockNextConnectionBehavior = Accept;
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "connect",
           "payload": {{
@@ -1336,7 +1337,7 @@ TEST_F(InspectorPackagerConnectionTest, TestRejectedPageConnection) {
           AtJsonPtr("/params", ElementsAre("arg1", "arg2"))))))
       .RetiresOnSaturation();
 
-  webSockets_[0]->getDelegate().didReceiveMessage(sformat(
+  webSockets_[0]->getDelegate().didReceiveMessage(std::format(
       R"({{
           "event": "wrappedEvent",
           "payload": {{
diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tests/JsiIntegrationTest.cpp b/packages/react-native/ReactCommon/jsinspector-modern/tests/JsiIntegrationTest.cpp
index 6fe1605bf8c..3f34540e105 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tests/JsiIntegrationTest.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tests/JsiIntegrationTest.cpp
@@ -8,13 +8,13 @@
 #include <folly/Format.h>
 #include <folly/executors/ManualExecutor.h>
 #include <folly/executors/QueuedImmediateExecutor.h>
+#include <format>
 
 #include "JsiIntegrationTest.h"
 #include "engines/JsiIntegrationTestGenericEngineAdapter.h"
 #include "engines/JsiIntegrationTestHermesEngineAdapter.h"
 
 using namespace ::testing;
-using folly::sformat;
 
 namespace facebook::react::jsinspector_modern {
 
@@ -486,7 +486,7 @@ TYPED_TEST(JsiIntegrationHermesTest, EvaluateExpressionInExecutionContext) {
                                            }
                                          }
                                        })"));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
         "id": 1,
         "method": "Runtime.evaluate",
@@ -508,7 +508,7 @@ TYPED_TEST(JsiIntegrationHermesTest, EvaluateExpressionInExecutionContext) {
   // Now the old execution context is stale.
   this->expectMessageFromPage(
       JsonParsed(AllOf(AtJsonPtr("/id", 3), AtJsonPtr("/error/code", -32600))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
         "id": 3,
         "method": "Runtime.evaluate",
@@ -731,7 +731,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObject) {
   // Ensure we can get the properties of the object.
   this->expectMessageFromPage(JsonParsed(
       AllOf(AtJsonPtr("/id", 2), AtJsonPtr("/result/result", SizeIs(Gt(0))))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 2,
           "method": "Runtime.getProperties",
@@ -744,7 +744,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObject) {
                                          "id": 3,
                                          "result": {}
                                        })"));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 3,
           "method": "Runtime.releaseObject",
@@ -755,7 +755,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObject) {
   // Getting properties for a released object results in an error.
   this->expectMessageFromPage(
       JsonParsed(AllOf(AtJsonPtr("/id", 4), AtJsonPtr("/error/code", -32000))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 4,
           "method": "Runtime.getProperties",
@@ -766,7 +766,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObject) {
   // Releasing an already released object is an error.
   this->expectMessageFromPage(
       JsonParsed(AllOf(AtJsonPtr("/id", 5), AtJsonPtr("/error/code", -32000))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 5,
           "method": "Runtime.releaseObject",
@@ -797,7 +797,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObjectGroup) {
   // Ensure we can get the properties of the object.
   this->expectMessageFromPage(JsonParsed(
       AllOf(AtJsonPtr("/id", 2), AtJsonPtr("/result/result", SizeIs(Gt(0))))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 2,
           "method": "Runtime.getProperties",
@@ -819,7 +819,7 @@ TYPED_TEST(JsiIntegrationHermesTest, ReleaseRemoteObjectGroup) {
   // Getting properties for a released object results in an error.
   this->expectMessageFromPage(
       JsonParsed(AllOf(AtJsonPtr("/id", 4), AtJsonPtr("/error/code", -32000))));
-  this->toPage_->sendMessage(sformat(
+  this->toPage_->sendMessage(std::format(
       R"({{
           "id": 4,
           "method": "Runtime.getProperties",
diff --git a/private/react-native-fantom/tester/src/main.cpp b/private/react-native-fantom/tester/src/main.cpp
index 58754619a9d..789f93ba02b 100644
--- a/private/react-native-fantom/tester/src/main.cpp
+++ b/private/react-native-fantom/tester/src/main.cpp
@@ -5,10 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include <fmt/format.h>
 #include <glog/logging.h>
 #include <yoga/YGEnums.h>
 #include <yoga/YGValue.h>
+#include <format>
 #include <iostream>
 
 int main() {
@@ -17,7 +17,7 @@ int main() {
 
   LOG(INFO) << "Hello, I am fantom_tester using glog!";
 
-  LOG(INFO) << fmt::format(
+  LOG(INFO) << std::format(
       "[Yoga] undefined == zero: {}", YGValueZero == YGValueUndefined);
 
   return 0;