diff --git a/packager/app/mpd_generator.cc b/packager/app/mpd_generator.cc
index 0b1c06b4c31..80073a86dc2 100644
--- a/packager/app/mpd_generator.cc
+++ b/packager/app/mpd_generator.cc
@@ -5,6 +5,7 @@
 // https://developers.google.com/open-source/licenses/bsd
 
 #include <iostream>
+#include <locale>
 
 #include "packager/app/mpd_generator_flags.h"
 #include "packager/app/vlog_flags.h"
@@ -20,7 +21,6 @@
 #if defined(OS_WIN)
 #include <codecvt>
 #include <functional>
-#include <locale>
 #endif  // defined(OS_WIN)
 
 DEFINE_bool(licenses, false, "Dump licenses.");
@@ -142,12 +142,20 @@ int wmain(int argc, wchar_t* argv[], wchar_t* envp[]) {
         delete[] utf8_args;
       });
   std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+
   for (int idx = 0; idx < argc; ++idx) {
     std::string utf8_arg(converter.to_bytes(argv[idx]));
     utf8_arg += '\0';
     utf8_argv[idx] = new char[utf8_arg.size()];
     memcpy(utf8_argv[idx], &utf8_arg[0], utf8_arg.size());
   }
+
+  // Because we just converted wide character args into UTF8, and because
+  // std::filesystem::u8path is used to interpret all std::string paths as
+  // UTF8, we should set the locale to UTF8 as well, for the transition point
+  // to C library functions like fopen to work correctly with non-ASCII paths.
+  std::setlocale(LC_ALL, ".UTF8");
+
   return shaka::MpdMain(argc, utf8_argv.get());
 }
 #else
diff --git a/packager/app/packager_main.cc b/packager/app/packager_main.cc
index a40c3d5dcc2..08df872773b 100644
--- a/packager/app/packager_main.cc
+++ b/packager/app/packager_main.cc
@@ -6,6 +6,7 @@
 
 #include <gflags/gflags.h>
 #include <iostream>
+#include <locale>
 
 #include "packager/app/ad_cue_generator_flags.h"
 #include "packager/app/crypto_flags.h"
@@ -34,7 +35,6 @@
 #if defined(OS_WIN)
 #include <codecvt>
 #include <functional>
-#include <locale>
 #endif  // defined(OS_WIN)
 
 DEFINE_bool(dump_stream_info, false, "Dump demuxed stream info.");
@@ -575,12 +575,20 @@ int wmain(int argc, wchar_t* argv[], wchar_t* envp[]) {
         delete[] utf8_args;
       });
   std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+
   for (int idx = 0; idx < argc; ++idx) {
     std::string utf8_arg(converter.to_bytes(argv[idx]));
     utf8_arg += '\0';
     utf8_argv[idx] = new char[utf8_arg.size()];
     memcpy(utf8_argv[idx], &utf8_arg[0], utf8_arg.size());
   }
+
+  // Because we just converted wide character args into UTF8, and because
+  // std::filesystem::u8path is used to interpret all std::string paths as
+  // UTF8, we should set the locale to UTF8 as well, for the transition point
+  // to C library functions like fopen to work correctly with non-ASCII paths.
+  std::setlocale(LC_ALL, ".UTF8");
+
   return shaka::PackagerMain(argc, utf8_argv.get());
 }
 #else
diff --git a/packager/file/file.cc b/packager/file/file.cc
index 8eef335d2a5..49d8f0f64e4 100644
--- a/packager/file/file.cc
+++ b/packager/file/file.cc
@@ -73,8 +73,8 @@ bool DeleteLocalFile(const char* file_name) {
 
 bool WriteLocalFileAtomically(const char* file_name,
                               const std::string& contents) {
-  const std::filesystem::path file_path(file_name);
-  const std::filesystem::path dir_path = file_path.parent_path();
+  const auto file_path = std::filesystem::u8path(file_name);
+  const auto dir_path = file_path.parent_path();
 
   std::string temp_file_name;
   if (!TempFilePath(dir_path.string(), &temp_file_name))
@@ -83,7 +83,8 @@ bool WriteLocalFileAtomically(const char* file_name,
     return false;
 
   std::error_code ec;
-  std::filesystem::rename(temp_file_name, file_name, ec);
+  auto temp_file_path = std::filesystem::u8path(temp_file_name);
+  std::filesystem::rename(temp_file_path, file_name, ec);
   if (ec) {
     LOG(ERROR) << "Failed to replace file '" << file_name << "' with '"
                << temp_file_name << "', error: " << ec;
@@ -405,7 +406,8 @@ bool File::IsLocalRegularFile(const char* file_name) {
     return false;
 
   std::error_code ec;
-  return std::filesystem::is_regular_file(real_file_name, ec);
+  auto real_file_path = std::filesystem::u8path(real_file_name);
+  return std::filesystem::is_regular_file(real_file_path, ec);
 }
 
 std::string File::MakeCallbackFileName(
diff --git a/packager/file/file_test_util.cc b/packager/file/file_test_util.cc
index 4726e57b6ff..3cfeafa1c34 100644
--- a/packager/file/file_test_util.cc
+++ b/packager/file/file_test_util.cc
@@ -16,8 +16,8 @@ std::string generate_unique_temp_path() {
   // Generate a unique name for a temporary file, using standard library
   // routines, to avoid a circular dependency on any of our own code for
   // generating temporary files.  The template must end in 6 X's.
-  std::filesystem::path temp_path_template =
-      (std::filesystem::temp_directory_path() / "packager-test.XXXXXX");
+  auto temp_path_template =
+      std::filesystem::temp_directory_path() / "packager-test.XXXXXX";
   std::string temp_path_template_string = temp_path_template.string();
 #if defined(OS_WIN)
   // _mktemp will modify the string passed to it to reflect the generated name
@@ -36,7 +36,7 @@ std::string generate_unique_temp_path() {
 
 void delete_file(const std::string& path) {
   std::error_code ec;
-  std::filesystem::remove(path, ec);
+  std::filesystem::remove(std::filesystem::u8path(path), ec);
   // Ignore errors.
 }
 
@@ -44,7 +44,7 @@ TempFile::TempFile() : path_(generate_unique_temp_path()) {}
 
 TempFile::~TempFile() {
   std::error_code ec;
-  std::filesystem::remove(path_, ec);
+  std::filesystem::remove(std::filesystem::u8path(path_), ec);
   // Ignore errors.
 }
 
diff --git a/packager/file/file_unittest.cc b/packager/file/file_unittest.cc
index 1ac9bac43af..c5af12dc766 100644
--- a/packager/file/file_unittest.cc
+++ b/packager/file/file_unittest.cc
@@ -10,6 +10,7 @@
 #include <sys/stat.h>
 
 #include <filesystem>
+#include <locale>
 
 #include "absl/flags/declare.h"
 #include "packager/file/file.h"
@@ -31,13 +32,14 @@ void WriteFile(const std::string& path, const std::string& data) {
 
 void DeleteFile(const std::string& path) {
   std::error_code ec;
-  std::filesystem::remove(path, ec);
+  std::filesystem::remove(std::filesystem::u8path(path), ec);
   // Ignore errors.
 }
 
 int64_t FileSize(const std::string& path) {
   std::error_code ec;
-  int64_t file_size = std::filesystem::file_size(path, ec);
+  int64_t file_size =
+      std::filesystem::file_size(std::filesystem::u8path(path), ec);
   if (ec) {
     return -1;
   }
@@ -65,6 +67,17 @@ namespace shaka {
 
 class LocalFileTest : public testing::Test {
  protected:
+  static std::string original_locale_;
+
+  static void SetUpTestSuite() {
+    original_locale_ = setlocale(LC_ALL, NULL);
+    setlocale(LC_ALL, ".UTF8");
+  }
+
+  static void TearDownTestSuite() {
+    setlocale(LC_ALL, original_locale_.c_str());
+  }
+
   void SetUp() override {
     data_.resize(kDataSize);
     for (int i = 0; i < kDataSize; ++i)
@@ -97,6 +110,9 @@ class LocalFileTest : public testing::Test {
   std::string local_file_name_;
 };
 
+// static
+std::string LocalFileTest::original_locale_;
+
 TEST_F(LocalFileTest, ReadNotExist) {
   // Remove test file if it exists.
   DeleteFile(local_file_name_no_prefix_);
@@ -233,6 +249,42 @@ TEST_F(LocalFileTest, IsLocalRegular) {
   ASSERT_TRUE(File::IsLocalRegularFile(local_file_name_.c_str()));
 }
 
+TEST_F(LocalFileTest, UnicodePath) {
+  // Delete the temp file already created.
+  DeleteFile(local_file_name_no_prefix_);
+
+  // Modify the local file name for this test to include non-ASCII characters.
+  // This is used in TearDown() to clean up the file we create in the test.
+  const std::string unicode_suffix = "από.txt";
+  local_file_name_ += unicode_suffix;
+  local_file_name_no_prefix_ += unicode_suffix;
+
+  // Write file using File API.
+  File* file = File::Open(local_file_name_.c_str(), "w");
+  ASSERT_TRUE(file != NULL);
+  EXPECT_EQ(kDataSize, file->Write(&data_[0], kDataSize));
+
+  // Check the size.
+  EXPECT_EQ(kDataSize, file->Size());
+  ASSERT_TRUE(file->Close());
+
+  // Open file using File API.
+  file = File::Open(local_file_name_.c_str(), "r");
+  ASSERT_TRUE(file != NULL);
+
+  // Read the entire file.
+  std::string read_data(kDataSize, 0);
+  EXPECT_EQ(kDataSize, file->Read(&read_data[0], kDataSize));
+
+  // Verify EOF.
+  uint8_t single_byte;
+  EXPECT_EQ(0, file->Read(&single_byte, sizeof(single_byte)));
+  ASSERT_TRUE(file->Close());
+
+  // Compare data written and read.
+  EXPECT_EQ(data_, read_data);
+}
+
 class ParamLocalFileTest : public LocalFileTest,
                            public ::testing::WithParamInterface<uint8_t> {};
 
diff --git a/packager/file/file_util.cc b/packager/file/file_util.cc
index fa5e31e4329..eb4656e81a0 100644
--- a/packager/file/file_util.cc
+++ b/packager/file/file_util.cc
@@ -43,7 +43,7 @@ std::string TempFileName() {
 }  // namespace
 
 bool TempFilePath(const std::string& temp_dir, std::string* temp_file_path) {
-  std::filesystem::path temp_dir_path(temp_dir);
+  auto temp_dir_path = std::filesystem::u8path(temp_dir);
   *temp_file_path = (temp_dir_path / TempFileName()).string();
   return true;
 }
diff --git a/packager/file/local_file.cc b/packager/file/local_file.cc
index e6d1f354c86..57318d0c528 100644
--- a/packager/file/local_file.cc
+++ b/packager/file/local_file.cc
@@ -75,7 +75,8 @@ int64_t LocalFile::Size() {
   }
 
   std::error_code ec;
-  int64_t file_size = std::filesystem::file_size(file_name(), ec);
+  auto file_path = std::filesystem::u8path(file_name());
+  int64_t file_size = std::filesystem::file_size(file_path, ec);
   if (ec) {
     LOG(ERROR) << "Cannot get file size, error: " << ec;
     return -1;
@@ -112,7 +113,7 @@ bool LocalFile::Tell(uint64_t* position) {
 LocalFile::~LocalFile() {}
 
 bool LocalFile::Open() {
-  std::filesystem::path file_path(file_name());
+  auto file_path = std::filesystem::u8path(file_name());
 
   // Create upper level directories for write mode.
   if (file_mode_.find("w") != std::string::npos) {
@@ -133,9 +134,10 @@ bool LocalFile::Open() {
 }
 
 bool LocalFile::Delete(const char* file_name) {
+  auto file_path = std::filesystem::u8path(file_name);
   std::error_code ec;
   // On error (ec truthy), remove() will return false anyway.
-  return std::filesystem::remove(file_name, ec);
+  return std::filesystem::remove(file_path, ec);
 }
 
 }  // namespace shaka
diff --git a/packager/media/base/container_names_unittest.cc b/packager/media/base/container_names_unittest.cc
index 517d0b85f93..0e88e9e9f4c 100644
--- a/packager/media/base/container_names_unittest.cc
+++ b/packager/media/base/container_names_unittest.cc
@@ -144,7 +144,7 @@ TEST(ContainerNamesTest, CheckFixedStrings) {
 
 // Determine the container type of a specified file.
 void TestFile(MediaContainerName expected, const std::string& name) {
-  std::filesystem::path path = GetTestDataFilePath(name);
+  auto path = GetTestDataFilePath(name);
   std::vector<uint8_t> data = ReadTestDataFile(name);
   ASSERT_FALSE(data.empty());
 
diff --git a/packager/media/test/test_data_util.cc b/packager/media/test/test_data_util.cc
index c06e4d81fe0..facfbf7f5d2 100644
--- a/packager/media/test/test_data_util.cc
+++ b/packager/media/test/test_data_util.cc
@@ -11,13 +11,13 @@ namespace media {
 
 // Returns a file path for a file in the media/test/data directory.
 std::filesystem::path GetTestDataFilePath(const std::string& name) {
-  std::filesystem::path data_dir(TEST_DATA_DIR);
+  auto data_dir = std::filesystem::u8path(TEST_DATA_DIR);
   return data_dir / name;
 }
 
 // Returns a file path for a file in the media/app/test/testdata directory.
 std::filesystem::path GetAppTestDataFilePath(const std::string& name) {
-  std::filesystem::path data_dir(TEST_DATA_DIR);
+  auto data_dir = std::filesystem::u8path(TEST_DATA_DIR);
   auto app_data_dir =
       data_dir.parent_path().parent_path() / "app" / "test" / "testdata";
   return app_data_dir / name;
@@ -25,7 +25,7 @@ std::filesystem::path GetAppTestDataFilePath(const std::string& name) {
 
 // Reads a test file from media/test/data directory and returns its content.
 std::vector<uint8_t> ReadTestDataFile(const std::string& name) {
-  std::filesystem::path path = GetTestDataFilePath(name);
+  auto path = GetTestDataFilePath(name);
 
   FILE* f = fopen(path.string().c_str(), "rb");
   if (!f) {