diff --git a/ui/base/l10n/l10n_util.cc b/ui/base/l10n/l10n_util.cc
index ad0ad0ed9d12..440ab1a04d4d 100644
--- a/ui/base/l10n/l10n_util.cc
+++ b/ui/base/l10n/l10n_util.cc
@@ -357,6 +357,10 @@ bool CheckAndResolveLocale(const std::string& locale,
     if (base::LowerCaseEqualsASCII(lang, "es") &&
         !base::LowerCaseEqualsASCII(region, "es")) {
       tmp_locale.append("-419");
+    } else if (base::LowerCaseEqualsASCII(lang, "pt")) {
+      // Map pt-RR other than pt-BR to pt-PT. Note that "pt" by itself maps to
+      // pt-BR (logic below).
+      tmp_locale.append("-PT");
     } else if (base::LowerCaseEqualsASCII(lang, "zh")) {
       // Map zh-HK and zh-MO to zh-TW. Otherwise, zh-FOO is mapped to zh-CN.
       if (base::LowerCaseEqualsASCII(region, "hk") ||
@@ -387,14 +391,13 @@ bool CheckAndResolveLocale(const std::string& locale,
   }
 
   // Google updater uses no, tl, iw and en for our nb, fil, he, and en-US.
+  // Note that pt-RR is mapped to pt-PT above, but we want pt -> pt-BR here.
   struct {
     const char* source;
     const char* dest;
   } alias_map[] = {
-      {"no", "nb"},
-      {"tl", "fil"},
-      {"iw", "he"},
-      {"en", "en-US"},
+      {"en", "en-US"}, {"iw", "he"},  {"no", "nb"},
+      {"pt", "pt-BR"}, {"tl", "fil"}, {"zh", "zh-CN"},
   };
   for (const auto& alias : alias_map) {
     if (base::LowerCaseEqualsASCII(lang, alias.source)) {
diff --git a/ui/base/l10n/l10n_util_unittest.cc b/ui/base/l10n/l10n_util_unittest.cc
index ab88a40ccb37..ee81f036888f 100644
--- a/ui/base/l10n/l10n_util_unittest.cc
+++ b/ui/base/l10n/l10n_util_unittest.cc
@@ -113,19 +113,8 @@ TEST_F(L10nUtilTest, GetAppLocale) {
   ASSERT_TRUE(PathService::Get(ui::DIR_LOCALES, &new_locale_dir));
   // Make fake locale files.
   std::string filenames[] = {
-    "en-US",
-    "en-GB",
-    "fr",
-    "es-419",
-    "es",
-    "zh-TW",
-    "zh-CN",
-    "he",
-    "fil",
-    "nb",
-    "am",
-    "ca",
-    "ca@valencia",
+      "am", "ca", "ca@valencia", "en-GB", "en-US", "es",    "es-419", "fil",
+      "fr", "he", "nb",          "pt-BR", "pt-PT", "zh-CN", "zh-TW",
   };
 
   for (size_t i = 0; i < arraysize(filenames); ++i) {
@@ -267,6 +256,22 @@ TEST_F(L10nUtilTest, GetAppLocale) {
     EXPECT_EQ("es", l10n_util::GetApplicationLocale(std::string()));
     EXPECT_STREQ("es", icu::Locale::getDefault().getLanguage());
 
+    SetDefaultLocaleForTest("pt-PT", env.get());
+    EXPECT_EQ("pt-PT", l10n_util::GetApplicationLocale(std::string()));
+    EXPECT_STREQ("pt", icu::Locale::getDefault().getLanguage());
+
+    SetDefaultLocaleForTest("pt-BR", env.get());
+    EXPECT_EQ("pt-BR", l10n_util::GetApplicationLocale(std::string()));
+    EXPECT_STREQ("pt", icu::Locale::getDefault().getLanguage());
+
+    SetDefaultLocaleForTest("pt-AO", env.get());
+    EXPECT_EQ("pt-PT", l10n_util::GetApplicationLocale(std::string()));
+    EXPECT_STREQ("pt", icu::Locale::getDefault().getLanguage());
+
+    SetDefaultLocaleForTest("pt", env.get());
+    EXPECT_EQ("pt-BR", l10n_util::GetApplicationLocale(std::string()));
+    EXPECT_STREQ("pt", icu::Locale::getDefault().getLanguage());
+
     SetDefaultLocaleForTest("zh-HK", env.get());
     EXPECT_EQ("zh-TW", l10n_util::GetApplicationLocale(std::string()));
     EXPECT_STREQ("zh", icu::Locale::getDefault().getLanguage());
@@ -279,6 +284,10 @@ TEST_F(L10nUtilTest, GetAppLocale) {
     EXPECT_EQ("zh-CN", l10n_util::GetApplicationLocale(std::string()));
     EXPECT_STREQ("zh", icu::Locale::getDefault().getLanguage());
 
+    SetDefaultLocaleForTest("zh", env.get());
+    EXPECT_EQ("zh-CN", l10n_util::GetApplicationLocale(std::string()));
+    EXPECT_STREQ("zh", icu::Locale::getDefault().getLanguage());
+
     SetDefaultLocaleForTest("en-CA", env.get());
     EXPECT_EQ("en-GB", l10n_util::GetApplicationLocale(std::string()));
     EXPECT_STREQ("en", icu::Locale::getDefault().getLanguage());