diff --git a/lib/mix/lib/mix/generator.ex b/lib/mix/lib/mix/generator.ex
index e2ccceb65ad..2551b8ecb38 100644
--- a/lib/mix/lib/mix/generator.ex
+++ b/lib/mix/lib/mix/generator.ex
@@ -27,6 +27,13 @@ defmodule Mix.Generator do
 
     if opts[:force] || overwrite?(path, contents) do
       File.mkdir_p!(Path.dirname(path))
+
+      contents =
+        case opts[:format_elixir] do
+          true -> [Code.format_string!(contents), ?\n]
+          _ -> contents
+        end
+
       File.write!(path, contents)
       true
     else
@@ -94,6 +101,7 @@ defmodule Mix.Generator do
 
     * `:force` - forces copying without a shell prompt
     * `:quiet` - does not log command output
+    * `:format_elixir` (since v1.18.0) - if `true`, apply formatter to the generated file
 
   ## Examples
 
diff --git a/lib/mix/test/mix/generator_test.exs b/lib/mix/test/mix/generator_test.exs
index 5b7dcca6433..e393471628b 100644
--- a/lib/mix/test/mix/generator_test.exs
+++ b/lib/mix/test/mix/generator_test.exs
@@ -147,6 +147,13 @@ defmodule Mix.GeneratorTest do
         assert_received {:mix_shell, :yes?, ["foo already exists, overwrite?"]}
       end)
     end
+
+    test "with `format_elixir: true`" do
+      in_tmp("create_file", fn ->
+        create_file("foo", "%{ foo:  :bar }", format_elixir: true)
+        assert File.read!("foo") == "%{foo: :bar}\n"
+      end)
+    end
   end
 
   describe "copy_file/3" do