diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 73856bafc9..752fe187f9 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -297,6 +297,12 @@ jobs:
           - jobname: linux-gcc-default
             cc: gcc
             pool: ubuntu-latest
+          - jobname: linux-clang-sanitize-leak
+            cc: clang
+            pool: ubuntu-latest
+          - jobname: linux-gcc-sanitize-leak
+            cc: gcc
+            pool: ubuntu-latest
     env:
       CC: ${{matrix.vector.cc}}
       jobname: ${{matrix.vector.jobname}}
diff --git a/Makefile b/Makefile
index 502e0c9a81..d4cad5136f 100644
--- a/Makefile
+++ b/Makefile
@@ -1216,6 +1216,9 @@ PTHREAD_CFLAGS =
 SPARSE_FLAGS ?=
 SP_EXTRA_FLAGS = -Wno-universal-initializer
 
+# For informing GIT-BUILD-OPTIONS of the SANITIZE=leak target
+SANITIZE_LEAK =
+
 # For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will
 # usually result in less CPU usage at the cost of higher peak memory.
 # Setting it to 0 will feed all files in a single spatch invocation.
@@ -1260,6 +1263,7 @@ BASIC_CFLAGS += -DSHA1DC_FORCE_ALIGNED_ACCESS
 endif
 ifneq ($(filter leak,$(SANITIZERS)),)
 BASIC_CFLAGS += -DSUPPRESS_ANNOTATED_LEAKS
+SANITIZE_LEAK = YesCompiledWithIt
 endif
 ifneq ($(filter address,$(SANITIZERS)),)
 NO_REGEX = NeededForASAN
@@ -2793,6 +2797,7 @@ GIT-BUILD-OPTIONS: FORCE
 	@echo NO_UNIX_SOCKETS=\''$(subst ','\'',$(subst ','\'',$(NO_UNIX_SOCKETS)))'\' >>$@+
 	@echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
 	@echo DC_SHA1=\''$(subst ','\'',$(subst ','\'',$(DC_SHA1)))'\' >>$@+
+	@echo SANITIZE_LEAK=\''$(subst ','\'',$(subst ','\'',$(SANITIZE_LEAK)))'\' >>$@+
 	@echo X=\'$(X)\' >>$@+
 ifdef TEST_OUTPUT_DIRECTORY
 	@echo TEST_OUTPUT_DIRECTORY=\''$(subst ','\'',$(subst ','\'',$(TEST_OUTPUT_DIRECTORY)))'\' >>$@+
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 67852d0d37..8ac72d7246 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -12,13 +12,13 @@ UBUNTU_COMMON_PKGS="make libssl-dev libcurl4-openssl-dev libexpat-dev
  libemail-valid-perl libio-socket-ssl-perl libnet-smtp-ssl-perl"
 
 case "$jobname" in
-linux-clang|linux-gcc)
+linux-clang|linux-gcc|linux-clang-sanitize-leak|linux-gcc-sanitize-leak)
 	sudo apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
 	sudo apt-get -q update
 	sudo apt-get -q -y install language-pack-is libsvn-perl apache2 \
 		$UBUNTU_COMMON_PKGS
 	case "$jobname" in
-	linux-gcc)
+	linux-gcc|linux-gcc-sanitize-leak)
 		sudo apt-get -q -y install gcc-8
 		;;
 	esac
diff --git a/ci/lib.sh b/ci/lib.sh
index 476c3f369f..bb02b5abf4 100755
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -183,14 +183,16 @@ export GIT_TEST_CLONE_2GB=true
 export SKIP_DASHED_BUILT_INS=YesPlease
 
 case "$jobname" in
-linux-clang|linux-gcc)
-	if [ "$jobname" = linux-gcc ]
-	then
+linux-clang|linux-gcc|linux-clang-sanitize-leak|linux-gcc-sanitize-leak)
+	case "$jobname" in
+	linux-gcc|linux-gcc-sanitize-leak)
 		export CC=gcc-8
 		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python3"
-	else
+		;;
+	*)
 		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python2"
-	fi
+		;;
+	esac
 
 	export GIT_TEST_HTTPD=true
 
@@ -233,4 +235,10 @@ linux-musl)
 	;;
 esac
 
+case "$jobname" in
+linux-clang-sanitize-leak|linux-gcc-sanitize-leak)
+	export SANITIZE=leak
+	;;
+esac
+
 MAKEFLAGS="$MAKEFLAGS CC=${CC:-cc}"
diff --git a/ci/run-build-and-tests.sh b/ci/run-build-and-tests.sh
index 3ce81ffee9..5fe047b5c6 100755
--- a/ci/run-build-and-tests.sh
+++ b/ci/run-build-and-tests.sh
@@ -12,7 +12,7 @@ esac
 
 make
 case "$jobname" in
-linux-gcc)
+linux-gcc|linux-gcc-sanitize-leak)
 	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 	make test
 	export GIT_TEST_SPLIT_INDEX=yes
@@ -29,7 +29,7 @@ linux-gcc)
 	export GIT_TEST_CHECKOUT_WORKERS=2
 	make test
 	;;
-linux-clang)
+linux-clang|linux-clang-sanitize-leak)
 	export GIT_TEST_DEFAULT_HASH=sha1
 	make test
 	export GIT_TEST_DEFAULT_HASH=sha256
diff --git a/t/README b/t/README
index 1a2072b2c8..303d0be817 100644
--- a/t/README
+++ b/t/README
@@ -448,6 +448,22 @@ GIT_TEST_CHECKOUT_WORKERS=<n> overrides the 'checkout.workers' setting
 to <n> and 'checkout.thresholdForParallelism' to 0, forcing the
 execution of the parallel-checkout code.
 
+GIT_TEST_SANITIZE_LEAK=<boolean> will force the tests to run when git
+is compiled with SANITIZE=leak (we pick it up via
+../GIT-BUILD-OPTIONS).
+
+By default all tests are skipped when compiled with SANITIZE=leak, and
+individual test scripts opt themselves in to leak testing by setting
+GIT_TEST_SANITIZE_LEAK=true before sourcing test-lib.sh. Within those
+tests use the SANITIZE_LEAK prerequisite to skip individiual tests
+(i.e. test_expect_success !SANITIZE_LEAK [...]).
+
+So the GIT_TEST_SANITIZE_LEAK setting is different in behavior from
+both other GIT_TEST_*=[true|false] settings, but more useful given how
+SANITIZE=leak works & the state of the test suite. Manually setting
+GIT_TEST_SANITIZE_LEAK=true is only useful during development when
+finding and fixing memory leaks.
+
 Naming Tests
 ------------
 
diff --git a/t/t5701-git-serve.sh b/t/t5701-git-serve.sh
index 930721f053..d58efb0aa9 100755
--- a/t/t5701-git-serve.sh
+++ b/t/t5701-git-serve.sh
@@ -243,7 +243,7 @@ test_expect_success 'unexpected lines are not allowed in fetch request' '
 
 # Test the basics of object-info
 #
-test_expect_success 'basics of object-info' '
+test_expect_success !SANITIZE_LEAK 'basics of object-info' '
 	test-tool pkt-line pack >in <<-EOF &&
 	command=object-info
 	object-format=$(test_oid algo)
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 7036f83b33..9201510e16 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1353,6 +1353,40 @@ then
 	exit 1
 fi
 
+# SANITIZE=leak test mode
+sanitize_leak_true=
+add_sanitize_leak_true () {
+	sanitize_leak_true="$sanitize_leak_true$1 "
+}
+
+sanitize_leak_false=
+add_sanitize_leak_false () {
+	sanitize_leak_false="$sanitize_leak_false$1 "
+}
+
+sanitize_leak_opt_in_msg="opt-in with GIT_TEST_SANITIZE_LEAK=true"
+maybe_skip_all_sanitize_leak () {
+	# Whitelist patterns
+	add_sanitize_leak_true 't000*'
+	add_sanitize_leak_true 't001*'
+	add_sanitize_leak_true 't006*'
+
+	# Blacklist patterns (overrides whitelist)
+	add_sanitize_leak_false 't000[469]*'
+	add_sanitize_leak_false 't001[2459]*'
+	add_sanitize_leak_false 't006[0248]*'
+
+	if match_pattern_list "$1" "$sanitize_leak_false"
+	then
+		skip_all="test $this_test on SANITIZE=leak blacklist, $sanitize_leak_opt_in_msg"
+		test_done
+	elif match_pattern_list "$1" "$sanitize_leak_true"
+	then
+		return 0
+	fi
+	return 1
+}
+
 # Are we running this test at all?
 remove_trash=
 this_test=${0##*/}
@@ -1364,6 +1398,31 @@ then
 	test_done
 fi
 
+# Aggressively skip non-whitelisted tests when compiled with
+# SANITIZE=leak
+if test -n "$SANITIZE_LEAK"
+then
+	if test -z "$GIT_TEST_SANITIZE_LEAK" &&
+		maybe_skip_all_sanitize_leak "$TEST_NAME"
+	then
+		say_color info >&3 "test $this_test on SANITIZE=leak whitelist"
+		GIT_TEST_SANITIZE_LEAK=true
+	fi
+
+	# We need to see it in "git env--helper" (via
+	# test_bool_env)
+	export GIT_TEST_SANITIZE_LEAK
+
+	if ! test_bool_env GIT_TEST_SANITIZE_LEAK false
+	then
+		skip_all="skip all tests in $this_test under SANITIZE=leak, $sanitize_leak_opt_in_msg"
+		test_done
+	fi
+elif test_bool_env GIT_TEST_SANITIZE_LEAK false
+then
+	error "GIT_TEST_SANITIZE_LEAK=true has no effect except when compiled with SANITIZE=leak"
+fi
+
 # Last-minute variable setup
 HOME="$TRASH_DIRECTORY"
 GNUPGHOME="$HOME/gnupg-home-not-used"
@@ -1516,6 +1575,7 @@ test -z "$NO_PYTHON" && test_set_prereq PYTHON
 test -n "$USE_LIBPCRE2" && test_set_prereq PCRE
 test -n "$USE_LIBPCRE2" && test_set_prereq LIBPCRE2
 test -z "$NO_GETTEXT" && test_set_prereq GETTEXT
+test -n "$SANITIZE_LEAK" && test_set_prereq SANITIZE_LEAK
 
 if test -z "$GIT_TEST_CHECK_CACHE_TREE"
 then
