diff --git a/packages/react-native/third-party-podspecs/fmt.podspec b/packages/react-native/third-party-podspecs/fmt.podspec
index 2f38990e226c..058a473820fd 100644
--- a/packages/react-native/third-party-podspecs/fmt.podspec
+++ b/packages/react-native/third-party-podspecs/fmt.podspec
@@ -17,6 +17,33 @@ Pod::Spec.new do |spec|
     :git => fmt_git_url,
     :tag => "11.0.2"
   }
+  # Patch fmt's existing "Apple clang < 14 broken" gate at
+  # `include/fmt/base.h:122` to catch ALL Apple clang versions. fmt 11.0.2's
+  # consteval `basic_format_string` constructor is rejected by Xcode 26.x's
+  # stricter constexpr evaluator, breaking the compile of `Pods/fmt/src/format.cc`
+  # at `format-inl.h:59`, `60`, `1387`, `1391`, `1394`, etc. with:
+  #
+  #   error: call to consteval function 'fmt::basic_format_string<...>'
+  #          is not a constant expression
+  #
+  # fmt already disables consteval for compilers it considers broken
+  # (Apple clang < 14, MSVC VS2019 < 16.10 etc. — see `base.h:113-132`) by
+  # forcing the `FMT_USE_CONSTEVAL=0` branch of its config chain. Widening
+  # the existing Apple-clang branch to drop the `< 14000029L` upper bound
+  # adds Xcode 26.x to that broken-list and falls back to fmt's constexpr
+  # path, which compiles cleanly. Notes:
+  #
+  # - An xcconfig `GCC_PREPROCESSOR_DEFINITIONS = FMT_USE_CONSTEVAL=0`
+  #   alone does NOT work: fmt's chain in `base.h:113-132` has no
+  #   `#ifndef FMT_USE_CONSTEVAL` guard and unconditionally redefines the
+  #   macro to `1` on any compiler that sets `__cpp_consteval`. Patching
+  #   the source is the only path that survives the preprocessor.
+  # - Long-term fix is a fmt 11.1+ bump (fmt's own upstream addressed the
+  #   stricter-eval interaction there). This `sed` is the minimal,
+  #   reversible workaround until that lands.
+  spec.prepare_command = <<-CMD
+    /usr/bin/sed -i.bak 's|defined(__apple_build_version__) && __apple_build_version__ < 14000029L|defined(__apple_build_version__)|' include/fmt/base.h
+  CMD
   spec.pod_target_xcconfig = {
     "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
     "GCC_WARN_INHIBIT_ALL_WARNINGS" => "YES" # Disable warnings because we don't control this library