diff --git a/actionpack/lib/action_dispatch.rb b/actionpack/lib/action_dispatch.rb
index 76377984a6..7ffc6472b3 100644
--- a/actionpack/lib/action_dispatch.rb
+++ b/actionpack/lib/action_dispatch.rb
@@ -67,6 +67,7 @@ module ActionDispatch
     autoload :PublicExceptions
     autoload :Reloader
     autoload :RemoteIp
+    autoload :ServerTiming
     autoload :ShowExceptions
     autoload :SSL
     autoload :Static
diff --git a/actionpack/lib/action_dispatch/middleware/server_timing.rb b/actionpack/lib/action_dispatch/middleware/server_timing.rb
new file mode 100644
index 0000000000..258f3cdd9d
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/server_timing.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "active_support/notifications"
+
+module ActionDispatch
+  class ServerTiming
+    SERVER_TIMING_HEADER = "Server-Timing"
+
+    def initialize(app)
+      @app = app
+    end
+
+    def call(env)
+      events = []
+      subscriber = ActiveSupport::Notifications.subscribe(/.*/) do |*args|
+        events << ActiveSupport::Notifications::Event.new(*args)
+      end
+
+      status, headers, body = begin
+        @app.call(env)
+      ensure
+        ActiveSupport::Notifications.unsubscribe(subscriber)
+      end
+
+      header_info = events.group_by(&:name).map do |event_name, events_collection|
+        "#{event_name};dur=#{events_collection.sum(&:duration)}"
+      end
+      headers[SERVER_TIMING_HEADER] = header_info.join(", ")
+
+      [ status, headers, body ]
+    end
+  end
+end
diff --git a/actionpack/test/dispatch/server_timing_test.rb b/actionpack/test/dispatch/server_timing_test.rb
new file mode 100644
index 0000000000..b66592fbc1
--- /dev/null
+++ b/actionpack/test/dispatch/server_timing_test.rb
@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+
+class ServerTimingTest < ActionDispatch::IntegrationTest
+  class TestController < ActionController::Base
+    def index
+      head :ok
+    end
+
+    def show
+      ActiveSupport::Notifications.instrument("custom.event") do
+        true
+      end
+      head :ok
+    end
+
+    def create
+      ActiveSupport::Notifications.instrument("custom.event") do
+        raise
+      end
+    end
+  end
+
+  test "server timing header is included in the response" do
+    with_test_route_set do
+      get "/"
+      assert_match(/\w+/, @response.headers["Server-Timing"])
+    end
+  end
+
+  test "includes default action controller events duration" do
+    with_test_route_set do
+      get "/"
+      assert_match(/start_processing.action_controller;dur=\w+/, @response.headers["Server-Timing"])
+      assert_match(/process_action.action_controller;dur=\w+/, @response.headers["Server-Timing"])
+    end
+  end
+
+  test "includes custom active support events duration" do
+    with_test_route_set do
+      get "/id"
+      assert_match(/custom.event;dur=\w+/, @response.headers["Server-Timing"])
+    end
+  end
+
+  test "ensures it doesn't leak subscriptions when the app crashes" do
+    with_test_route_set do
+      post "/"
+      assert_not ActiveSupport::Notifications.notifier.listening?("custom.event")
+    end
+  end
+
+  private
+    def with_test_route_set
+      with_routing do |set|
+        set.draw do
+          get "/", to: ::ServerTimingTest::TestController.action(:index)
+          get "/id", to: ::ServerTimingTest::TestController.action(:show)
+          post "/", to: ::ServerTimingTest::TestController.action(:create)
+        end
+
+        @app = self.class.build_app(set) do |middleware|
+          middleware.use ActionDispatch::ServerTiming
+        end
+
+        yield
+      end
+    end
+end
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index 4414d170c0..f83df20a8b 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -21,7 +21,7 @@ module Rails
                     :read_encrypted_secrets, :log_level, :content_security_policy_report_only,
                     :content_security_policy_nonce_generator, :content_security_policy_nonce_directives,
                     :require_master_key, :credentials, :disable_sandbox, :add_autoload_paths_to_load_path,
-                    :rake_eager_load
+                    :rake_eager_load, :server_timing
 
       attr_reader :encoding, :api_only, :loaded_config_version
 
@@ -74,6 +74,7 @@ module Rails
         @add_autoload_paths_to_load_path         = true
         @permissions_policy                      = nil
         @rake_eager_load                         = false
+        @server_timing                           = false
       end
 
       # Loads default configurations. See {the result of the method for each version}[https://guides.rubyonrails.org/configuring.html#results-of-config-load-defaults].
diff --git a/railties/lib/rails/application/default_middleware_stack.rb b/railties/lib/rails/application/default_middleware_stack.rb
index eddd3432c7..daaa009f69 100644
--- a/railties/lib/rails/application/default_middleware_stack.rb
+++ b/railties/lib/rails/application/default_middleware_stack.rb
@@ -42,6 +42,7 @@ module Rails
 
           middleware.use ::ActionDispatch::Executor, app.executor
 
+          middleware.use ::ActionDispatch::ServerTiming if config.server_timing
           middleware.use ::Rack::Runtime
           middleware.use ::Rack::MethodOverride unless config.api_only
           middleware.use ::ActionDispatch::RequestId, header: config.action_dispatch.request_id_header
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
index 623070be48..fa1bd04579 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
@@ -14,6 +14,9 @@ Rails.application.configure do
   # Show full error reports.
   config.consider_all_requests_local = true
 
+  # Enable server timing
+  config.server_timing = true
+
   # Enable/disable caching. By default caching is disabled.
   # Run rails dev:cache to toggle caching.
   if Rails.root.join("tmp/caching-dev.txt").exist?
diff --git a/railties/test/application/middleware_test.rb b/railties/test/application/middleware_test.rb
index f015938a19..fdc088f0a0 100644
--- a/railties/test/application/middleware_test.rb
+++ b/railties/test/application/middleware_test.rb
@@ -21,6 +21,7 @@ module ApplicationTests
 
     test "default middleware stack" do
       add_to_config "config.active_record.migration_error = :page_load"
+      add_to_config "config.server_timing = true"
 
       boot!
 
@@ -63,6 +64,7 @@ module ApplicationTests
         "Rack::Sendfile",
         "ActionDispatch::Static",
         "ActionDispatch::Executor",
+        "ActionDispatch::ServerTiming",
         "ActiveSupport::Cache::Strategy::LocalCache",
         "Rack::Runtime",
         "Rack::MethodOverride",