diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index a273921d8e34a..d843f0eaf3eb7 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -30,6 +30,10 @@ class Doctor < AbstractCommand
       def run
         Homebrew.inject_dump_stats!(Diagnostic::Checks, /^check_*/) if args.audit_debug?
 
+        # While it is probably OK to run an outdated Xcode for normal operations,
+        # it's good to know if we have an outdated Xcode when running `brew doctor`.
+        ENV.delete("HOMEBREW_NO_WARN_OUTDATED_XCODE")
+
         checks = Diagnostic::Checks.new(verbose: args.verbose?)
 
         if args.list_checks?
diff --git a/Library/Homebrew/env_config.rb b/Library/Homebrew/env_config.rb
index bb185001b30a5..d0411830b744a 100644
--- a/Library/Homebrew/env_config.rb
+++ b/Library/Homebrew/env_config.rb
@@ -397,6 +397,10 @@ module EnvConfig
                      "from homebrew-core.",
         boolean:     true,
       },
+      HOMEBREW_NO_WARN_OUTDATED_XCODE:           {
+        description: "If set, Homebrew will not warn about using outdated (but still compatible) Xcode versions.",
+        boolean:     true,
+      },
       HOMEBREW_PIP_INDEX_URL:                    {
         description:  "If set, `brew install` <formula> will use this URL to download PyPI package resources.",
         default_text: "`https://pypi.org/simple`.",
diff --git a/Library/Homebrew/extend/os/mac/diagnostic.rb b/Library/Homebrew/extend/os/mac/diagnostic.rb
index fa714f68ec56e..a162711f0b93e 100644
--- a/Library/Homebrew/extend/os/mac/diagnostic.rb
+++ b/Library/Homebrew/extend/os/mac/diagnostic.rb
@@ -139,6 +139,8 @@ def check_xcode_up_to_date
         # Homebrew/brew is currently using.
         return if GitHub::Actions.env_set?
 
+        return if ENV["HOMEBREW_NO_WARN_OUTDATED_XCODE"]
+
         # With fake El Capitan for Portable Ruby, we are intentionally not using Xcode 8.
         # This is because we are not using the CLT and Xcode 8 has the 10.12 SDK.
         return if ENV["HOMEBREW_FAKE_MACOS"]