diff --git a/libcxx/include/__format/format_context.h b/libcxx/include/__format/format_context.h
--- a/libcxx/include/__format/format_context.h
+++ b/libcxx/include/__format/format_context.h
@@ -22,13 +22,13 @@
 #include <__iterator/back_insert_iterator.h>
 #include <__iterator/concepts.h>
 #include <__memory/addressof.h>
+#include <__memory/construct_at.h>
 #include <__utility/move.h>
 #include <__variant/monostate.h>
 #include <cstddef>
 
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
-#include <locale>
-#include <optional>
+#  include <locale>
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -44,20 +44,92 @@
 class _LIBCPP_TEMPLATE_VIS basic_format_context;
 
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
+
+namespace __format {
+// [format.context]/6
+// std::locale locale();
+//   Returns: The locale passed to the formatting function if the latter
+//   takes one, and std::locale() otherwise.
+//
+// This class is a helper to implement this behaviour. The call to
+// std::locale() is done once and only when needed.
+class __locale {
+public:
+  _LIBCPP_HIDE_FROM_ABI __locale() : __dummy_{'\0'}, __engaged_{false} {}
+  _LIBCPP_HIDE_FROM_ABI __locale(locale __loc) : __loc_{__loc}, __engaged_{true} {}
+
+  _LIBCPP_HIDE_FROM_ABI ~__locale() {
+    if (__engaged_)
+      __loc_.~locale();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __locale(const __locale& __other) noexcept : __dummy_{'\0'}, __engaged_(__other.__engaged_) {
+    if (__engaged_)
+      std::construct_at(std::addressof(__loc_), __other.__loc_);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __locale(__locale&& __other) noexcept : __dummy_{'\0'}, __engaged_(__other.__engaged_) {
+    // Note locale is not movable.
+    if (__engaged_)
+      __loc_ = __other.__loc_;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __locale& operator=(const __locale& __other) noexcept {
+    __assign(__other);
+    return *this;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI __locale& operator=(__locale&& __other) noexcept {
+    __assign(__other);
+    return *this;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI locale __value() {
+    if (!__engaged_) {
+      std::construct_at(std::addressof(__loc_), locale());
+      __engaged_ = true;
+    }
+
+    return __loc_;
+  }
+
+private:
+  union {
+    char __dummy_;
+    locale __loc_;
+  };
+
+  bool __engaged_;
+
+  _LIBCPP_HIDE_FROM_ABI void __assign(const __locale& __other) noexcept {
+    // Note locale is not movable.
+    if (__engaged_) {
+      if (__other.__engaged_)
+        __loc_ = __other.__loc_;
+      else {
+        __loc_.~locale();
+        __engaged_ = false;
+      }
+    } else if (__other.__engaged_) {
+      std::construct_at(std::addressof(__loc_), __other.__loc_);
+      __engaged_ = true;
+    }
+    // Both not engaged do nothing.
+  }
+};
+} // namespace __format
+
 /**
  * Helper to create a basic_format_context.
  *
  * This is needed since the constructor is private.
  */
 template <class _OutIt, class _CharT>
-_LIBCPP_HIDE_FROM_ABI basic_format_context<_OutIt, _CharT>
-__format_context_create(
-    _OutIt __out_it,
-    basic_format_args<basic_format_context<_OutIt, _CharT>> __args,
-    optional<_VSTD::locale>&& __loc = nullopt) {
-  return _VSTD::basic_format_context(_VSTD::move(__out_it), __args, _VSTD::move(__loc));
+_LIBCPP_HIDE_FROM_ABI basic_format_context<_OutIt, _CharT> __format_context_create(
+    _OutIt __out_it, basic_format_args<basic_format_context<_OutIt, _CharT>> __args, __format::__locale __loc = {}) {
+  return _VSTD::basic_format_context(_VSTD::move(__out_it), __args, __loc);
 }
-#else
+#  else
 template <class _OutIt, class _CharT>
 _LIBCPP_HIDE_FROM_ABI basic_format_context<_OutIt, _CharT>
 __format_context_create(
@@ -65,7 +137,7 @@
     basic_format_args<basic_format_context<_OutIt, _CharT>> __args) {
   return _VSTD::basic_format_context(_VSTD::move(__out_it), __args);
 }
-#endif
+#  endif
 
 using format_context =
     basic_format_context<back_insert_iterator<__format::__output_buffer<char>>,
@@ -95,12 +167,8 @@
     return __args_.get(__id);
   }
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
-  _LIBCPP_HIDE_FROM_ABI _VSTD::locale locale() {
-    if (!__loc_)
-      __loc_ = _VSTD::locale{};
-    return *__loc_;
-  }
-#endif
+  _LIBCPP_HIDE_FROM_ABI _VSTD::locale locale() { return __loc_.__value(); }
+#  endif
   _LIBCPP_HIDE_FROM_ABI iterator out() { return std::move(__out_it_); }
   _LIBCPP_HIDE_FROM_ABI void advance_to(iterator __it) { __out_it_ = std::move(__it); }
 
@@ -109,30 +177,17 @@
   basic_format_args<basic_format_context> __args_;
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
 
-  // The Standard doesn't specify how the locale is stored.
-  // [format.context]/6
-  // std::locale locale();
-  //   Returns: The locale passed to the formatting function if the latter
-  //   takes one, and std::locale() otherwise.
-  // This is done by storing the locale of the constructor in this optional. If
-  // locale() is called and the optional has no value the value will be created.
-  // This allows the implementation to lazily create the locale.
-  // TODO FMT Validate whether lazy creation is the best solution.
-  optional<_VSTD::locale> __loc_;
+  __format::__locale __loc_;
 
   template <class __OutIt, class __CharT>
   friend _LIBCPP_HIDE_FROM_ABI basic_format_context<__OutIt, __CharT>
-  __format_context_create(__OutIt, basic_format_args<basic_format_context<__OutIt, __CharT>>,
-                          optional<_VSTD::locale>&&);
+  __format_context_create(__OutIt, basic_format_args<basic_format_context<__OutIt, __CharT>>, __format::__locale __loc);
 
   // Note: the Standard doesn't specify the required constructors.
-  _LIBCPP_HIDE_FROM_ABI
-  explicit basic_format_context(_OutIt __out_it,
-                                basic_format_args<basic_format_context> __args,
-                                optional<_VSTD::locale>&& __loc)
-      : __out_it_(_VSTD::move(__out_it)), __args_(__args),
-        __loc_(_VSTD::move(__loc)) {}
-#else
+  _LIBCPP_HIDE_FROM_ABI explicit basic_format_context(
+      _OutIt __out_it, basic_format_args<basic_format_context> __args, __format::__locale __loc)
+      : __out_it_(_VSTD::move(__out_it)), __args_(__args), __loc_(__loc) {}
+#  else
   template <class __OutIt, class __CharT>
   friend _LIBCPP_HIDE_FROM_ABI basic_format_context<__OutIt, __CharT>
       __format_context_create(__OutIt, basic_format_args<basic_format_context<__OutIt, __CharT>>);
@@ -141,7 +196,7 @@
   explicit basic_format_context(_OutIt __out_it,
                                 basic_format_args<basic_format_context> __args)
       : __out_it_(_VSTD::move(__out_it)), __args_(__args) {}
-#endif
+#  endif
 };
 
 // A specialization for __retarget_buffer
diff --git a/libcxx/include/module.modulemap.in b/libcxx/include/module.modulemap.in
--- a/libcxx/include/module.modulemap.in
+++ b/libcxx/include/module.modulemap.in
@@ -910,7 +910,6 @@
       module format_args                     { private header "__format/format_args.h" }
       module format_context {
         private header "__format/format_context.h"
-        export optional
         export locale
         export __locale
       }
diff --git a/libcxx/test/libcxx/transitive_includes/cxx03.csv b/libcxx/test/libcxx/transitive_includes/cxx03.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx03.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx03.csv
@@ -328,7 +328,6 @@
 format initializer_list
 format limits
 format locale
-format optional
 format queue
 format stack
 format stdexcept
diff --git a/libcxx/test/libcxx/transitive_includes/cxx11.csv b/libcxx/test/libcxx/transitive_includes/cxx11.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx11.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx11.csv
@@ -328,7 +328,6 @@
 format initializer_list
 format limits
 format locale
-format optional
 format queue
 format stack
 format stdexcept
diff --git a/libcxx/test/libcxx/transitive_includes/cxx14.csv b/libcxx/test/libcxx/transitive_includes/cxx14.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx14.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx14.csv
@@ -330,7 +330,6 @@
 format initializer_list
 format limits
 format locale
-format optional
 format queue
 format stack
 format stdexcept
diff --git a/libcxx/test/libcxx/transitive_includes/cxx17.csv b/libcxx/test/libcxx/transitive_includes/cxx17.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx17.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx17.csv
@@ -330,7 +330,6 @@
 format initializer_list
 format limits
 format locale
-format optional
 format queue
 format stack
 format stdexcept
diff --git a/libcxx/test/libcxx/transitive_includes/cxx20.csv b/libcxx/test/libcxx/transitive_includes/cxx20.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx20.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx20.csv
@@ -120,7 +120,6 @@
 chrono ctime
 chrono limits
 chrono locale
-chrono optional
 chrono ostream
 chrono ratio
 chrono sstream
@@ -337,7 +336,6 @@
 format initializer_list
 format limits
 format locale
-format optional
 format queue
 format stack
 format stdexcept
diff --git a/libcxx/test/libcxx/transitive_includes/cxx2b.csv b/libcxx/test/libcxx/transitive_includes/cxx2b.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx2b.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx2b.csv
@@ -73,7 +73,6 @@
 chrono limits
 chrono locale
 chrono new
-chrono optional
 chrono ostream
 chrono ratio
 chrono sstream
@@ -227,7 +226,6 @@
 format limits
 format locale
 format new
-format optional
 format queue
 format stack
 format stdexcept