diff --git a/Library/Homebrew/Gemfile b/Library/Homebrew/Gemfile
index 2c494287fc..4f2872b628 100644
--- a/Library/Homebrew/Gemfile
+++ b/Library/Homebrew/Gemfile
@@ -4,7 +4,7 @@ source "https://rubygems.org"
 
 # The default case (no envs), should always be a restrictive bound on the lowest supported minor version.
 # This is the branch that Dependabot will use.
-if ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", "").empty?
+if ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", "").empty? && ENV.fetch("HOMEBREW_RUBY3", "").empty?
   ruby "~> 2.6.0"
 else
   ruby ">= 2.6.0"
diff --git a/Library/Homebrew/cleanup.rb b/Library/Homebrew/cleanup.rb
index 8c39af2c64..50cbba762f 100644
--- a/Library/Homebrew/cleanup.rb
+++ b/Library/Homebrew/cleanup.rb
@@ -465,7 +465,11 @@ module Homebrew
 
     def cleanup_portable_ruby
       vendor_dir = HOMEBREW_LIBRARY/"Homebrew/vendor"
-      portable_ruby_latest_version = (vendor_dir/"portable-ruby-version").read.chomp
+      portable_ruby_latest_version = if ENV["HOMEBREW_RUBY3"]
+        (vendor_dir/"portable-ruby-version").read.chomp
+      else
+        "2.6.10_1"
+      end
 
       portable_rubies_to_remove = []
       Pathname.glob(vendor_dir/"portable-ruby/*.*").select(&:directory?).each do |path|
@@ -488,7 +492,9 @@ module Homebrew
       end
     end
 
-    def use_system_ruby?; end
+    def use_system_ruby?
+      false
+    end
 
     def cleanup_bootsnap
       bootsnap = cache/"bootsnap"
diff --git a/Library/Homebrew/cmd/vendor-install.sh b/Library/Homebrew/cmd/vendor-install.sh
index 285bf698b1..b0b1ece3f2 100644
--- a/Library/Homebrew/cmd/vendor-install.sh
+++ b/Library/Homebrew/cmd/vendor-install.sh
@@ -20,19 +20,37 @@ then
      # use a x86_64 Portable Ruby.
      [[ "${HOMEBREW_PHYSICAL_PROCESSOR}" == "arm64" && "${HOMEBREW_PREFIX}" == "/usr/local" ]]
   then
-    ruby_FILENAME="portable-ruby-2.6.10_1.el_capitan.bottle.tar.gz"
-    ruby_SHA="61029cec31c68a1fae1fa90fa876adf43d0becff777da793f9b5c5577f00567a"
+    if [[ -n "${HOMEBREW_RUBY3}" ]]
+    then
+      ruby_FILENAME="portable-ruby-3.1.4.el_capitan.bottle.tar.gz"
+      ruby_SHA="02180ca8b8295422ae84921bcf034b7ee8ce5575488bd5e6a37a192e53cd5d34"
+    else
+      ruby_FILENAME="portable-ruby-2.6.10_1.el_capitan.bottle.tar.gz"
+      ruby_SHA="61029cec31c68a1fae1fa90fa876adf43d0becff777da793f9b5c5577f00567a"
+    fi
   elif [[ "${HOMEBREW_PHYSICAL_PROCESSOR}" == "arm64" ]]
   then
-    ruby_FILENAME="portable-ruby-2.6.10_1.arm64_big_sur.bottle.tar.gz"
-    ruby_SHA="905b0c3896164ae8067a22fff2fd0b80b16d3c8bb72441403eedf69da71ec717"
+    if [[ -n "${HOMEBREW_RUBY3}" ]]
+    then
+      ruby_FILENAME="portable-ruby-3.1.4.arm64_big_sur.bottle.tar.gz"
+      ruby_SHA="d783cbeb6e6ef0d71c0b442317b54554370decd6fac66bf2d4938c07a63f67be"
+    else
+      ruby_FILENAME="portable-ruby-2.6.10_1.arm64_big_sur.bottle.tar.gz"
+      ruby_SHA="905b0c3896164ae8067a22fff2fd0b80b16d3c8bb72441403eedf69da71ec717"
+    fi
   fi
 elif [[ -n "${HOMEBREW_LINUX}" ]]
 then
   case "${HOMEBREW_PROCESSOR}" in
     x86_64)
-      ruby_FILENAME="portable-ruby-2.6.10_1.x86_64_linux.bottle.tar.gz"
-      ruby_SHA="68923daf3e139482b977c3deba63a3b54ea37bb5f716482948878819ef911bad"
+      if [[ -n "${HOMEBREW_RUBY3}" ]]
+      then
+        ruby_FILENAME="portable-ruby-3.1.4.x86_64_linux.bottle.tar.gz"
+        ruby_SHA="f7be167f7ac4f296b9f4c5874ceeea4aafd9999c3c7f2b0378cae7dd273e2322"
+      else
+        ruby_FILENAME="portable-ruby-2.6.10_1.x86_64_linux.bottle.tar.gz"
+        ruby_SHA="68923daf3e139482b977c3deba63a3b54ea37bb5f716482948878819ef911bad"
+      fi
       ;;
     *) ;;
   esac
@@ -53,8 +71,13 @@ then
   fi
   ruby_URLs+=(
     "https://ghcr.io/v2/homebrew/portable-ruby/portable-ruby/blobs/sha256:${ruby_SHA}"
-    "https://github.com/Homebrew/homebrew-portable-ruby/releases/download/2.6.10_1/${ruby_FILENAME}"
   )
+  if [[ -n "${HOMEBREW_RUBY3}" ]]
+  then
+    ruby_URLs+=("https://github.com/Homebrew/homebrew-portable-ruby/releases/download/3.1.4/${ruby_FILENAME}")
+  else
+    ruby_URLs+=("https://github.com/Homebrew/homebrew-portable-ruby/releases/download/2.6.10_1/${ruby_FILENAME}")
+  fi
   ruby_URL="${ruby_URLs[0]}"
 fi
 
@@ -300,7 +323,12 @@ homebrew-vendor-install() {
   VENDOR_FILENAME="${!filename_var}"
   VENDOR_SHA="${!sha_var}"
   VENDOR_URL="${!url_var}"
-  VENDOR_VERSION="$(cat "${VENDOR_DIR}/portable-${VENDOR_NAME}-version")"
+  if [[ -z "${HOMEBREW_RUBY3}" && "${VENDOR_NAME}" == "ruby" ]]
+  then
+    VENDOR_VERSION="2.6.10_1" # EOL - phasing out
+  else
+    VENDOR_VERSION="$(cat "${VENDOR_DIR}/portable-${VENDOR_NAME}-version")"
+  fi
 
   if [[ -z "${VENDOR_URL}" || -z "${VENDOR_SHA}" ]]
   then
diff --git a/Library/Homebrew/dev-cmd/tests.rb b/Library/Homebrew/dev-cmd/tests.rb
index d170366784..100f39d922 100644
--- a/Library/Homebrew/dev-cmd/tests.rb
+++ b/Library/Homebrew/dev-cmd/tests.rb
@@ -208,6 +208,7 @@ module Homebrew
       HOMEBREW_CACHE
       HOMEBREW_LOGS
       HOMEBREW_TEMP
+      HOMEBREW_RUBY3
     ]
     allowed_test_env << "HOMEBREW_USE_RUBY_FROM_PATH" if Homebrew::EnvConfig.developer?
     Homebrew::EnvConfig::ENVS.keys.map(&:to_s).each do |env|
diff --git a/Library/Homebrew/extend/os/linux/cleanup.rb b/Library/Homebrew/extend/os/linux/cleanup.rb
index d486f6a112..17eb8c162c 100644
--- a/Library/Homebrew/extend/os/linux/cleanup.rb
+++ b/Library/Homebrew/extend/os/linux/cleanup.rb
@@ -6,7 +6,7 @@ module Homebrew
     undef use_system_ruby?
 
     def use_system_ruby?
-      return false if Homebrew::EnvConfig.force_vendor_ruby?
+      return false if Homebrew::EnvConfig.force_vendor_ruby? || ENV["HOMEBREW_RUBY3"]
 
       rubies = [which("ruby"), which("ruby", ORIGINAL_PATHS)].compact
       system_ruby = Pathname.new("/usr/bin/ruby")
diff --git a/Library/Homebrew/extend/os/mac/cleanup.rb b/Library/Homebrew/extend/os/mac/cleanup.rb
index 8fa20b62af..ea63f03095 100644
--- a/Library/Homebrew/extend/os/mac/cleanup.rb
+++ b/Library/Homebrew/extend/os/mac/cleanup.rb
@@ -6,7 +6,7 @@ module Homebrew
     undef use_system_ruby?
 
     def use_system_ruby?
-      return false if Homebrew::EnvConfig.force_vendor_ruby?
+      return false if Homebrew::EnvConfig.force_vendor_ruby? || ENV["HOMEBREW_RUBY3"]
 
       ENV["HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH"].present?
     end
diff --git a/Library/Homebrew/startup/bootsnap.rb b/Library/Homebrew/startup/bootsnap.rb
index 30064f196e..3bc34ea970 100644
--- a/Library/Homebrew/startup/bootsnap.rb
+++ b/Library/Homebrew/startup/bootsnap.rb
@@ -3,7 +3,9 @@
 
 # Disable Rails cops, as we haven't required active_support yet.
 # rubocop:disable Rails
-homebrew_bootsnap_enabled = ENV["HOMEBREW_NO_BOOTSNAP"].nil? && !ENV["HOMEBREW_BOOTSNAP"].nil?
+homebrew_bootsnap_enabled = ENV["HOMEBREW_NO_BOOTSNAP"].nil? &&
+                            !ENV["HOMEBREW_BOOTSNAP"].nil? &&
+                            ENV["HOMEBREW_RUBY3"].nil?
 
 # we need some development tools to build bootsnap native code
 homebrew_bootsnap_enabled &&= if ENV["HOMEBREW_MACOS_VERSION"]
diff --git a/Library/Homebrew/test/rubocop_spec.rb b/Library/Homebrew/test/rubocop_spec.rb
index ce163c2d98..1d62593814 100644
--- a/Library/Homebrew/test/rubocop_spec.rb
+++ b/Library/Homebrew/test/rubocop_spec.rb
@@ -9,6 +9,7 @@ describe "RuboCop" do
         allowlist = %w[
           HOMEBREW_TESTS
           HOMEBREW_USE_RUBY_FROM_PATH
+          HOMEBREW_RUBY3
         ]
         ENV.delete(key) if key.start_with?("HOMEBREW_") && allowlist.exclude?(key)
       end
diff --git a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
index bf488562d7..3bb9b4ae5a 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
@@ -78,13 +78,15 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
     ].compact.join(File::PATH_SEPARATOR)
 
     env.merge!(
-      "PATH"                      => path,
-      "HOMEBREW_PATH"             => path,
-      "HOMEBREW_BREW_FILE"        => HOMEBREW_PREFIX/"bin/brew",
-      "HOMEBREW_INTEGRATION_TEST" => command_id_from_args(args),
-      "HOMEBREW_TEST_TMPDIR"      => TEST_TMPDIR,
-      "HOMEBREW_DEV_CMD_RUN"      => "true",
-      "GEM_HOME"                  => nil,
+      "PATH"                        => path,
+      "HOMEBREW_PATH"               => path,
+      "HOMEBREW_BREW_FILE"          => HOMEBREW_PREFIX/"bin/brew",
+      "HOMEBREW_INTEGRATION_TEST"   => command_id_from_args(args),
+      "HOMEBREW_TEST_TMPDIR"        => TEST_TMPDIR,
+      "HOMEBREW_DEV_CMD_RUN"        => "true",
+      "HOMEBREW_USE_RUBY_FROM_PATH" => ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", nil),
+      "HOMEBREW_RUBY3"              => ENV.fetch("HOMEBREW_RUBY3", nil),
+      "GEM_HOME"                    => nil,
     )
 
     @ruby_args ||= begin
@@ -129,8 +131,12 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
   end
 
   def brew_sh(*args)
+    env = {
+      "HOMEBREW_USE_RUBY_FROM_PATH" => ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", nil),
+      "HOMEBREW_RUBY3"              => ENV.fetch("HOMEBREW_RUBY3", nil),
+    }
     Bundler.with_unbundled_env do
-      stdout, stderr, status = Open3.capture3("#{ENV.fetch("HOMEBREW_PREFIX")}/bin/brew", *args)
+      stdout, stderr, status = Open3.capture3(env, "#{ENV.fetch("HOMEBREW_PREFIX")}/bin/brew", *args)
       $stdout.print stdout
       $stderr.print stderr
       status
diff --git a/Library/Homebrew/utils/ruby.sh b/Library/Homebrew/utils/ruby.sh
index b8573b1705..ec76d66933 100644
--- a/Library/Homebrew/utils/ruby.sh
+++ b/Library/Homebrew/utils/ruby.sh
@@ -70,7 +70,7 @@ find_ruby() {
 # HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH are set by brew.sh
 # shellcheck disable=SC2154
 need_vendored_ruby() {
-  if [[ -n "${HOMEBREW_FORCE_VENDOR_RUBY}" ]]
+  if [[ -n "${HOMEBREW_FORCE_VENDOR_RUBY}" || -n "${HOMEBREW_RUBY3}" ]]
   then
     return 0
   elif [[ -n "${HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH}" ]] && ! can_use_ruby_from_path
@@ -118,7 +118,12 @@ If there's no Homebrew Portable Ruby available for your processor:
   vendor_ruby_root="${vendor_dir}/portable-ruby/current"
   vendor_ruby_path="${vendor_ruby_root}/bin/ruby"
   vendor_ruby_terminfo="${vendor_ruby_root}/share/terminfo"
-  vendor_ruby_latest_version="$(cat "${vendor_dir}/portable-ruby-version")"
+  if [[ -n "${HOMEBREW_RUBY3}" ]]
+  then
+    vendor_ruby_latest_version="$(cat "${vendor_dir}/portable-ruby-version")"
+  else
+    vendor_ruby_latest_version="2.6.10_1" # EOL - phasing out
+  fi
   vendor_ruby_current_version="$(readlink "${vendor_ruby_root}")"
 
   unset HOMEBREW_RUBY_PATH
diff --git a/Library/Homebrew/vendor/portable-ruby-version b/Library/Homebrew/vendor/portable-ruby-version
index 7d8b9aebdf..0aec50e6ed 100644
--- a/Library/Homebrew/vendor/portable-ruby-version
+++ b/Library/Homebrew/vendor/portable-ruby-version
@@ -1 +1 @@
-2.6.10_1
+3.1.4