diff --git a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
index 579ef65680d..86c68fcd0ca 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
@@ -15,6 +15,14 @@
   <section xml:id="sec-release-22.05-highlights">
     <title>Highlights</title>
     <itemizedlist>
+      <listitem>
+        <para>
+          The <literal>firefox</literal> browser on
+          <literal>x86_64-linux</literal> is now making use of
+          profile-guided optimization resulting in a much more
+          responsive browsing experience.
+        </para>
+      </listitem>
       <listitem>
         <para>
           <literal>security.acme.defaults</literal> has been added to
diff --git a/nixos/doc/manual/release-notes/rl-2205.section.md b/nixos/doc/manual/release-notes/rl-2205.section.md
index ba4d4c78049..f1bb091b892 100644
--- a/nixos/doc/manual/release-notes/rl-2205.section.md
+++ b/nixos/doc/manual/release-notes/rl-2205.section.md
@@ -6,6 +6,10 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 ## Highlights {#sec-release-22.05-highlights}
 
+- The `firefox` browser on `x86_64-linux` is now making use of
+  profile-guided optimization resulting in a much more responsive
+  browsing experience.
+
 - `security.acme.defaults` has been added to simplify configuring
   settings for many certificates at once. This also opens up the
   the option to use DNS-01 validation when using `enableACME` on
diff --git a/pkgs/applications/networking/browsers/firefox/common.nix b/pkgs/applications/networking/browsers/firefox/common.nix
index 64cba1b52a6..8d445ac44eb 100644
--- a/pkgs/applications/networking/browsers/firefox/common.nix
+++ b/pkgs/applications/networking/browsers/firefox/common.nix
@@ -83,6 +83,7 @@
 , gssSupport ? true, libkrb5
 , jemallocSupport ? true, jemalloc
 , ltoSupport ? (stdenv.isLinux && stdenv.is64bit), overrideCC, buildPackages
+, pgoSupport ? (stdenv.isLinux && stdenv.isx86_64 && stdenv.hostPlatform == stdenv.buildPlatform), xvfb-run
 , pipewireSupport ? waylandSupport && webrtcSupport
 , pulseaudioSupport ? stdenv.isLinux, libpulseaudio
 , waylandSupport ? true, libxkbcommon, libdrm
@@ -164,6 +165,13 @@ buildStdenv.mkDerivation ({
 
   inherit src unpackPhase meta;
 
+  # Add another configure-build-profiling run before the final configure phase if we build with pgo
+  preConfigurePhases = lib.optionals pgoSupport [
+    "configurePhase"
+    "buildPhase"
+    "profilingPhase"
+  ];
+
   patches = [
   ]
   ++ lib.optional (lib.versionAtLeast version "86") ./env_var_for_system_dir-ff86.patch
@@ -199,6 +207,7 @@ buildStdenv.mkDerivation ({
     which
     wrapGAppsHook
   ]
+  ++ lib.optionals pgoSupport [ xvfb-run ]
   ++ extraNativeBuildInputs;
 
   setOutputFlags = false; # `./mach configure` doesn't understand `--*dir=` flags.
@@ -214,6 +223,9 @@ buildStdenv.mkDerivation ({
     export MOZ_OBJDIR=$(pwd)/mozobj
     export MOZBUILD_STATE_PATH=$(pwd)/mozbuild
 
+    # Don't try to send libnotify notifications during build
+    export MOZ_NOSPAM=1
+
     # Set consistent remoting name to ensure wmclass matches with desktop file
     export MOZ_APP_REMOTINGNAME="${binaryName}"
 
@@ -228,6 +240,25 @@ buildStdenv.mkDerivation ({
     # RBox WASM Sandboxing
     export WASM_CC=${pkgsCross.wasi32.stdenv.cc}/bin/${pkgsCross.wasi32.stdenv.cc.targetPrefix}cc
     export WASM_CXX=${pkgsCross.wasi32.stdenv.cc}/bin/${pkgsCross.wasi32.stdenv.cc.targetPrefix}c++
+ '' + lib.optionalString pgoSupport ''
+   if [ -e "$TMPDIR/merged.profdata" ]; then
+     echo "Configuring with profiling data"
+     for i in "''${!configureFlagsArray[@]}"; do
+       if [[ ''${configureFlagsArray[i]} = "--enable-profile-generate=cross" ]]; then
+         unset 'configureFlagsArray[i]'
+       fi
+     done
+     configureFlagsArray+=(
+       "--enable-profile-use=cross"
+       "--with-pgo-profile-path="$TMPDIR/merged.profdata""
+       "--with-pgo-jarlog="$TMPDIR/jarlog""
+     )
+   else
+     echo "Configuring to generate profiling data"
+     configureFlagsArray+=(
+       "--enable-profile-generate=cross"
+     )
+   fi
   '' + lib.optionalString googleAPISupport ''
     # Google API key used by Chromium and Firefox.
     # Note: These are for NixOS/nixpkgs use ONLY. For your own distribution,
@@ -336,10 +367,35 @@ buildStdenv.mkDerivation ({
   ++ lib.optional  jemallocSupport jemalloc
   ++ extraBuildInputs;
 
+  profilingPhase = lib.optionalString pgoSupport ''
+    # Package up Firefox for profiling
+    ./mach package
+
+    # Run profiling
+    (
+      export HOME=$TMPDIR
+      export LLVM_PROFDATA=llvm-profdata
+      export JARLOG_FILE="$TMPDIR/jarlog"
+
+      xvfb-run -w 10 -s "-screen 0 1920x1080x24" \
+        ./mach python ./build/pgo/profileserver.py
+    )
+
+    # Copy profiling data to a place we can easily reference
+    cp ./merged.profdata $TMPDIR/merged.profdata
+
+    # Clean build dir
+    ./mach clobber
+  '';
+
   preBuild = ''
     cd mozobj
   '';
 
+  postBuild = ''
+    cd ..
+  '';
+
   makeFlags = extraMakeFlags;
   separateDebugInfo = enableDebugSymbols;
   enableParallelBuilding = true;
@@ -347,6 +403,10 @@ buildStdenv.mkDerivation ({
   # tests were disabled in configureFlags
   doCheck = false;
 
+  preInstall = ''
+    cd mozobj
+  '';
+
   postInstall = lib.optionalString buildStdenv.isLinux ''
     # Remove SDK cruft. FIXME: move to a separate output?
     rm -rf $out/share/idl $out/include $out/lib/${binaryName}-devel-*