diff --git a/flang/README.md b/flang/README.md
--- a/flang/README.md
+++ b/flang/README.md
@@ -109,6 +109,12 @@
 ninja
 ```
 
+By default flang tests that do not specify an explicit `--target` flag use
+LLVM's default target triple. For these tests, if there is a need to test on a
+different triple by overriding the default, the following needs to be added to
+the cmake command above:
+`-DLLVM_TARGET_TRIPLE_ENV="<some string>" -DFLANG_TEST_TARGET_TRIPLE="<your triple>"`.
+
 To run the flang tests on this build, execute the command in the "build"
 directory:
 ```bash
diff --git a/flang/test/CMakeLists.txt b/flang/test/CMakeLists.txt
--- a/flang/test/CMakeLists.txt
+++ b/flang/test/CMakeLists.txt
@@ -100,3 +100,11 @@
     PARAMS ${FLANG_TEST_PARAMS}
     DEPENDS ${FLANG_TEST_DEPENDS})
 endif()
+
+# To modify the default target triple for flang tests.
+if (DEFINED FLANG_TEST_TARGET_TRIPLE)
+  if (NOT DEFINED LLVM_TARGET_TRIPLE_ENV OR LLVM_TARGET_TRIPLE_ENV STREQUAL "")
+    message(FATAL_ERROR "LLVM_TARGET_TRIPLE_ENV must also be defined in order "
+                        "to use FLANG_TEST_TARGET_TRIPLE.")
+  endif()
+endif()
diff --git a/flang/test/Unit/lit.cfg.py b/flang/test/Unit/lit.cfg.py
--- a/flang/test/Unit/lit.cfg.py
+++ b/flang/test/Unit/lit.cfg.py
@@ -30,3 +30,8 @@
 
 # Propagate PYTHON_EXECUTABLE into the environment
 #config.environment['PYTHON_EXECUTABLE'] = sys.executable
+
+# To modify the default target triple for flang tests.
+if config.flang_test_triple:
+    config.target_triple = config.flang_test_triple
+    config.environment[config.llvm_target_triple_env] = config.flang_test_triple
diff --git a/flang/test/Unit/lit.site.cfg.py.in b/flang/test/Unit/lit.site.cfg.py.in
--- a/flang/test/Unit/lit.site.cfg.py.in
+++ b/flang/test/Unit/lit.site.cfg.py.in
@@ -2,6 +2,7 @@
 
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
+config.llvm_target_triple_env = "@LLVM_TARGET_TRIPLE_ENV@"
 config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
 config.llvm_libs_dir = lit_config.substitute("@LLVM_LIBS_DIR@")
 config.llvm_build_mode = lit_config.substitute("@LLVM_BUILD_MODE@")
@@ -9,6 +10,7 @@
 config.flang_obj_root = "@FLANG_BINARY_DIR@"
 config.flang_src_root = "@FLANG_SOURCE_DIR@"
 config.flang_libs_dir = "@LLVM_LIBRARY_OUTPUT_INTDIR@"
+config.flang_test_triple = "@FLANG_TEST_TARGET_TRIPLE@"
 config.flang_tools_dir = "@LLVM_RUNTIME_OUTPUT_INTDIR@"
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
diff --git a/flang/test/lit.cfg.py b/flang/test/lit.cfg.py
--- a/flang/test/lit.cfg.py
+++ b/flang/test/lit.cfg.py
@@ -45,6 +45,11 @@
 for arch in config.targets_to_build.split():
     config.available_features.add(arch.lower() + '-registered-target')
 
+# To modify the default target triple for flang tests.
+if config.flang_test_triple:
+    config.target_triple = config.flang_test_triple
+    config.environment[config.llvm_target_triple_env] = config.flang_test_triple
+
 # excludes: A list of directories to exclude from the testsuite. The 'Inputs'
 # subdirectories contain auxiliary inputs for various tests in their parent
 # directories.
diff --git a/flang/test/lit.site.cfg.py.in b/flang/test/lit.site.cfg.py.in
--- a/flang/test/lit.site.cfg.py.in
+++ b/flang/test/lit.site.cfg.py.in
@@ -5,6 +5,7 @@
 config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
 config.llvm_shlib_dir = lit_config.substitute(path(r"@SHLIBDIR@"))
 config.llvm_plugin_ext = "@LLVM_PLUGIN_EXT@"
+config.llvm_target_triple_env = "@LLVM_TARGET_TRIPLE_ENV@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.errc_messages = "@LLVM_LIT_ERRC_MESSAGES@"
 config.flang_obj_root = "@FLANG_BINARY_DIR@"
@@ -13,6 +14,7 @@
 config.flang_intrinsic_modules_dir = "@FLANG_INTRINSIC_MODULES_DIR@"
 config.flang_llvm_tools_dir = "@CMAKE_BINARY_DIR@/bin"
 config.flang_lib_dir = "@CMAKE_BINARY_DIR@/lib"
+config.flang_test_triple = "@FLANG_TEST_TARGET_TRIPLE@"
 config.flang_examples = @FLANG_BUILD_EXAMPLES@
 config.python_executable = "@PYTHON_EXECUTABLE@"
 config.flang_standalone_build = @FLANG_STANDALONE_BUILD@