diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7d67103ef8c..4e4ad337f04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,6 +42,7 @@ option(EXPERIMENTAL_TREAT_WARNINGS_AS_ERRORS "Additional compiler warnings are t
 indicate danger points where you should verify with the S2N-TLS developers that the security of
 the library is not compromised. These warnings are currently failing for some builds; once the problems are fixed,
 they will be moved to UNSAFE_TREAT_WARNINGS_AS_ERRORS." OFF)
+option(TSAN "Enable ThreadSanitizer to test thread safety" OFF)
 
 # Turn BUILD_TESTING=ON by default
 include(CTest)
@@ -220,6 +221,11 @@ if(S2N_UNSAFE_FUZZING_MODE)
     target_compile_options(${PROJECT_NAME} PRIVATE -fsanitize-coverage=trace-pc-guard -fsanitize=address,undefined,leak -fuse-ld=gold -DS2N_ADDRESS_SANITIZER=1)
 endif()
 
+if(TSAN)
+    target_compile_options(${PROJECT_NAME} PUBLIC -fsanitize=thread)
+    target_link_options(${PROJECT_NAME} PUBLIC -fsanitize=thread)
+endif()
+
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
 
 if (NOT $ENV{S2N_LIBCRYPTO} MATCHES "awslc")
@@ -497,6 +503,17 @@ if (BUILD_TESTING)
     file (GLOB TEST_LD_PRELOAD "tests/LD_PRELOAD/*.c")
     add_library(allocator_overrides SHARED ${TEST_LD_PRELOAD})
 
+    set(UNIT_TEST_ENVS S2N_DONT_MLOCK=1)
+    if(TSAN)
+        set(TSAN_SUPPRESSIONS_FILE ${CMAKE_SOURCE_DIR}/tests/.tsan_suppressions)
+        if(NOT EXISTS ${TSAN_SUPPRESSIONS_FILE})
+            message(FATAL_ERROR "TSAN suppression file ${TSAN_SUPPRESSIONS_FILE} missing")
+        endif()
+        set(UNIT_TEST_ENVS ${UNIT_TEST_ENVS} S2N_ADDRESS_SANITIZER=1)
+        set(UNIT_TEST_ENVS ${UNIT_TEST_ENVS} TSAN_OPTIONS=suppressions=${TSAN_SUPPRESSIONS_FILE})
+    endif()
+    message(STATUS "Running tests with environment: ${UNIT_TEST_ENVS}")
+
     file(GLOB UNITTESTS_SRC "tests/unit/*.c")
     foreach(test_case ${UNITTESTS_SRC})
         string(REGEX REPLACE ".+\\/(.+)\\.c" "\\1" test_case_name ${test_case})
@@ -520,18 +537,7 @@ if (BUILD_TESTING)
         endif()
         add_test(NAME ${test_case_name} COMMAND $<TARGET_FILE:${test_case_name}> WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests/unit)
         set_property(TEST ${test_case_name} PROPERTY LABELS "unit")
-
-        set_property(
-        TEST
-            ${test_case_name}
-        PROPERTY
-            ENVIRONMENT LD_PRELOAD=$<TARGET_FILE:allocator_overrides>)
-
-        set_property(
-        TEST
-            ${test_case_name}
-        PROPERTY
-            ENVIRONMENT S2N_DONT_MLOCK=1)
+        set_property(TEST ${test_case_name} PROPERTY ENVIRONMENT ${UNIT_TEST_ENVS})
 
     endforeach(test_case)
 
diff --git a/codebuild/spec/buildspec_tsan.yml b/codebuild/spec/buildspec_tsan.yml
new file mode 100644
index 00000000000..6aaf00efaa9
--- /dev/null
+++ b/codebuild/spec/buildspec_tsan.yml
@@ -0,0 +1,25 @@
+---
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You may not use
+# this file except in compliance with the License. A copy of the License is
+# located at
+#
+# http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing permissions and
+# limitations under the License.
+version: 0.2
+
+phases:
+  build:
+    on-failure: ABORT
+    commands:
+      - cmake . -Bbuild -DTSAN=on
+      - cmake --build ./build -j $(nproc)
+  post_build:
+    on-failure: ABORT
+    commands:
+      - CTEST_OUTPUT_ON_FAILURE=1 CTEST_PARALLEL_LEVEL=$(nproc) make -C build test
diff --git a/tests/.tsan_suppressions b/tests/.tsan_suppressions
new file mode 100644
index 00000000000..1498f4ab77e
--- /dev/null
+++ b/tests/.tsan_suppressions
@@ -0,0 +1,2 @@
+# We don't care about the thread safety of our test count
+race:test_count