diff --git a/CMakeLists.txt b/CMakeLists.txt
index a7d422d3646..886c6366043 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,7 @@ option(S2N_LTO, "Enables link time optimizations when building s2n-tls." OFF)
 option(S2N_STACKTRACE "Enables stacktrace functionality in s2n-tls. Note that this functionality is
 only available on platforms that support execinfo." ON)
 option(COVERAGE "Enable profiling collection for code coverage calculation" OFF)
+option(BUILD_TESTING "Build tests for s2n-tls. By default only unit tests are built." ON)
 option(S2N_INTEG_TESTS "Enable the integrationv2 tests" OFF)
 option(S2N_FAST_INTEG_TESTS "Enable the integrationv2 with more parallelism, only has effect if S2N_INTEG_TESTS=ON" ON)
 option(S2N_INSTALL_S2NC_S2ND "Install the binaries s2nc and s2nd" OFF)
@@ -41,9 +42,6 @@ option(TSAN "Enable ThreadSanitizer to test thread safety" OFF)
 option(ASAN "Enable AddressSanitizer to test memory safety" OFF)
 option(SECCOMP "Link with seccomp and run seccomp tests" OFF)
 
-# Turn BUILD_TESTING=ON by default
-include(CTest)
-
 file(GLOB API_HEADERS "api/*.h")
 file(GLOB API_UNSTABLE_HEADERS "api/unstable/*.h")
 
@@ -497,6 +495,29 @@ if (BUILD_TESTING)
     ########################## configure unit tests ############################
     ############################################################################
 
+    # CTest configuration variables need to be set before include(CTest) is called
+    set(VALGRIND_DEFAULT " \
+        --leak-check=full \
+        --leak-resolution=high \
+        --trace-children=yes \
+        -q --error-exitcode=123 \
+        --error-limit=no \
+        --num-callers=40 \
+        --undef-value-errors=no \
+        --log-fd=2 \
+        --suppressions=valgrind.suppressions")
+
+    # "pedantic valgrind" will error on memory that is "Still Reachable". 
+    # We only run this on OpenSSL 1.1.1 because there are hundreds of false positives in other libcryptos.
+    # Tracking issue: https://github.com/aws/s2n-tls/issues/4777
+    if ($ENV{S2N_LIBCRYPTO} MATCHES "openssl-1.1.1")
+        set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT} --run-libc-freeres=yes --errors-for-leak-kinds=all --show-leak-kinds=all")
+    else()
+        set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT} --run-libc-freeres=no")
+    endif()
+
+    set(MEMORYCHECK_TYPE "Valgrind")
+
     set(UNIT_TEST_ENVS S2N_DONT_MLOCK=1)
     if (TSAN OR ASAN)
         set(UNIT_TEST_ENVS ${UNIT_TEST_ENVS} S2N_ADDRESS_SANITIZER=1)
@@ -525,6 +546,8 @@ if (BUILD_TESTING)
     endif()
     message(STATUS "Running tests with environment: ${UNIT_TEST_ENVS}")
 
+    include(CTest)
+
     ############################################################################
     ############################ build unit tests ##############################
     ############################################################################
diff --git a/codebuild/spec/buildspec_valgrind.yml b/codebuild/spec/buildspec_valgrind.yml
new file mode 100644
index 00000000000..01c9b21bb9b
--- /dev/null
+++ b/codebuild/spec/buildspec_valgrind.yml
@@ -0,0 +1,72 @@
+---
+# 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
+
+batch:
+  build-list:
+    - identifier: gcc_awslc
+      env:
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu22codebuild
+        variables:
+          S2N_LIBCRYPTO: awslc
+          COMPILER: gcc
+    - identifier: gcc_openssl_3_0
+      env:
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu22codebuild
+        variables:
+          S2N_LIBCRYPTO: openssl-3.0
+          COMPILER: gcc
+    - identifier: gcc_openssl_1_1_1
+      env:
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu18codebuild
+        variables:
+          S2N_LIBCRYPTO: openssl-1.1.1
+          COMPILER: gcc
+    - identifier: gcc_openssl_1_0_2
+      env:
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu22codebuild
+        variables:
+          S2N_LIBCRYPTO: openssl-1.0.2
+          COMPILER: gcc
+
+phases:
+  pre_build:
+    commands:
+      - |
+        if [ -d "third-party-src" ]; then
+          cd third-party-src;
+        fi
+      - /usr/bin/$COMPILER --version
+  build:
+    on-failure: ABORT
+    commands:
+      - |
+        cmake . -Bbuild \
+          -DCMAKE_C_COMPILER=/usr/bin/$COMPILER \
+          -DCMAKE_PREFIX_PATH=/usr/local/$S2N_LIBCRYPTO \
+          -DCMAKE_BUILD_TYPE=RelWithDebInfo
+      - cmake --build ./build -- -j $(nproc)
+  post_build:
+    on-failure: ABORT
+    commands:
+      - |
+        S2N_VALGRIND=1 \
+        CTEST_PARALLEL_LEVEL=$(nproc) \
+        CTEST_OUTPUT_ON_FAILURE=1 \
+        cmake --build build/ --target test \
+          -- ARGS="--test-action memcheck"
diff --git a/tests/unit/valgrind.suppressions b/tests/unit/valgrind.suppressions
index 3662410a9bf..e0f90fd05cb 100644
--- a/tests/unit/valgrind.suppressions
+++ b/tests/unit/valgrind.suppressions
@@ -1,13 +1,48 @@
-# It looks like valgrind may generate false positives on pthreads: https://stackoverflow.com/a/13132968
+# Valgrind may generate false positives on pthreads: https://stackoverflow.com/a/13132968
+# Without these suppressions, the following tests will fail:
+# s2n_examples_test, s2n_fork_generation_number_test, s2n_init_test, s2n_key_update_threads_test, and s2n_random_test.
 {
-   pthred_false_positive
+   pthread_false_positive
    Memcheck:Leak
    match-leak-kinds: possible
    fun:calloc
+   ...
    fun:allocate_dtv
    fun:_dl_allocate_tls
    fun:allocate_stack
-   fun:pthread_create@@GLIBC_2.2.5
+   fun:pthread_create@@*
+   ...
+   fun:main
+}
+
+# This memory leak is believed to be caused by backtrace() loading libgcc dynamically.
+# See https://man7.org/linux/man-pages/man3/backtrace_symbols_fd.3.html
+# We were unable to find any relevant bug reports. However, testing showed that the memory
+# leak didn't scale with the number of calls to backtrace(), both supporting this theory and
+# limiting the potential impact of the leak.
+{
+   stacktrace_suppression
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:malloc
+   fun:malloc
+   fun:_dlfo_mappings_segment_allocate
+   fun:_dl_find_object_update_1
+   fun:_dl_find_object_update
+   fun:dl_open_worker_begin
+   fun:_dl_catch_exception
+   fun:dl_open_worker
+   fun:_dl_catch_exception
+   fun:_dl_open
+   fun:do_dlopen
+   fun:_dl_catch_exception
+   fun:_dl_catch_error
+   fun:dlerror_run
+   fun:__libc_dlopen_mode
+   fun:__libc_unwind_link_get
+   ...
+   fun:backtrace
+   ...
    fun:main
 }