diff --git a/libcxx/src/filesystem/operations.cpp b/libcxx/src/filesystem/operations.cpp
--- a/libcxx/src/filesystem/operations.cpp
+++ b/libcxx/src/filesystem/operations.cpp
@@ -1235,6 +1235,11 @@
     return err.report(errc::not_a_directory, "path \"%s\" is not a directory",
                       p);
 
+  // https://llvm.org/PR45307:
+  // Avoid returning a temporary path with a trailing slash.
+  auto last_component = --p.end();
+  if (last_component->empty())
+    return p.parent_path();
   return p;
 }
 
diff --git a/libcxx/test/libcxx/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/trailing-slash.sh.cpp b/libcxx/test/libcxx/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/trailing-slash.sh.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/trailing-slash.sh.cpp
@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// https://llvm.org/PR45307
+//
+// Make sure that temp_directory_path() doesn't return a path with a trailing
+// slash, even when one of the relevant environment variables contains a path
+// with a trailing slash.
+
+// UNSUPPORTED: c++98, c++03
+
+// The dylibs shipped until and including macosx10.15 did not contain the fix
+// for this issue, so they fail at runtime.
+// XFAIL: with_system_cxx_lib=macosx10.15
+// XFAIL: with_system_cxx_lib=macosx10.14
+// XFAIL: with_system_cxx_lib=macosx10.13
+// XFAIL: with_system_cxx_lib=macosx10.12
+// XFAIL: with_system_cxx_lib=macosx10.11
+// XFAIL: with_system_cxx_lib=macosx10.10
+// XFAIL: with_system_cxx_lib=macosx10.9
+// XFAIL: with_system_cxx_lib=macosx10.8
+// XFAIL: with_system_cxx_lib=macosx10.7
+
+// RUN: %build
+// RUN: mkdir -p "%t.dir"
+// RUN: %exec env TMPDIR="%t.dir/" %t.exe "%t.dir"
+// RUN: %exec env TMP="%t.dir/" %t.exe "%t.dir"
+// RUN: %exec env TEMP="%t.dir/" %t.exe "%t.dir"
+// RUN: %exec env TEMPDIR="%t.dir/" %t.exe "%t.dir"
+
+#include <cassert>
+#include <filesystem>
+
+int main(int, char** argv) {
+  std::filesystem::path expected_tmp = argv[1];
+  std::filesystem::path tmp = std::filesystem::temp_directory_path();
+  assert(tmp == expected_tmp);
+  return 0;
+}