diff --git a/intl/locale/Quotes.cpp b/intl/locale/Quotes.cpp
new file mode 100644
index 000000000000..9379f18a14ec
--- /dev/null
+++ b/intl/locale/Quotes.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode:nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Quotes.h"
+#include "MozLocale.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+#include "nsDataHashtable.h"
+#include "nsPrintfCString.h"
+
+using namespace mozilla;
+using namespace mozilla::intl;
+
+namespace {
+struct LangQuotesRec {
+  const char* mLangs;
+  Quotes mQuotes;
+};
+
+#include "cldr-quotes.inc"
+
+static StaticAutoPtr<nsDataHashtable<nsCStringHashKey, Quotes>> sQuotesForLang;
+}  // anonymous namespace
+
+namespace mozilla {
+namespace intl {
+
+const Quotes* QuotesForLang(const nsAtom* aLang) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // On first use, initialize the hashtable from our CLDR-derived data array.
+  if (!sQuotesForLang) {
+    sQuotesForLang = new nsDataHashtable<nsCStringHashKey, Quotes>(32);
+    ClearOnShutdown(&sQuotesForLang);
+    for (const auto& i : sLangQuotes) {
+      const char* s = i.mLangs;
+      size_t len;
+      while ((len = strlen(s))) {
+        sQuotesForLang->Put(nsDependentCString(s, len), i.mQuotes);
+        s += len + 1;
+      }
+    }
+  }
+
+  nsAtomCString langStr(aLang);
+  const Quotes* entry = sQuotesForLang->GetValue(langStr);
+  if (entry) {
+    // Found an exact match for the requested lang.
+    return entry;
+  }
+
+  // Try parsing lang as a Locale (which will also canonicalize case of the
+  // subtags), then see if we can match it with region or script subtags,
+  // if present, or just the primary language tag.
+  Locale loc(langStr);
+  if (loc.IsWellFormed()) {
+    if (!loc.GetRegion().IsEmpty() &&
+        (entry = sQuotesForLang->GetValue(nsPrintfCString(
+             "%s-%s", loc.GetLanguage().get(), loc.GetRegion().get())))) {
+      return entry;
+    }
+    if (!loc.GetScript().IsEmpty() &&
+        (entry = sQuotesForLang->GetValue(nsPrintfCString(
+             "%s-%s", loc.GetLanguage().get(), loc.GetScript().get())))) {
+      return entry;
+    }
+    if ((entry = sQuotesForLang->GetValue(loc.GetLanguage()))) {
+      return entry;
+    }
+  }
+
+  return nullptr;
+}
+
+}  // namespace intl
+}  // namespace mozilla
diff --git a/intl/locale/Quotes.h b/intl/locale/Quotes.h
new file mode 100644
index 000000000000..7bd7d277ca27
--- /dev/null
+++ b/intl/locale/Quotes.h
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode:nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_intl_Quotes_h__
+#define mozilla_intl_Quotes_h__
+
+#include "nsAtom.h"
+
+namespace mozilla {
+namespace intl {
+
+// Currently, all the quotation characters provided by CLDR are single BMP
+// codepoints, so they fit into char16_t fields. If there are ever multi-
+// character strings or non-BMP codepoints in a future version, we'll need
+// to extend this to a larger/more flexible structure, but for now it's
+// deliberately kept simple and lightweight.
+struct Quotes {
+  // Entries in order [open, close, alternativeOpen, alternativeClose]
+  char16_t mChars[4];
+};
+
+/**
+ * Return a pointer to the Quotes record for the given locale (lang attribute),
+ * or nullptr if none available.
+ * The returned value points to a hashtable entry, but will remain valid until
+ * shutdown begins, as the table is not modified after initialization.
+ */
+const Quotes* QuotesForLang(const nsAtom* aLang);
+
+}  // namespace intl
+}  // namespace mozilla
+
+#endif  // mozilla_intl_Quotes_h__
diff --git a/intl/locale/cldr-quotes.inc b/intl/locale/cldr-quotes.inc
new file mode 100644
index 000000000000..bc2d9f9de285
--- /dev/null
+++ b/intl/locale/cldr-quotes.inc
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Derived from the Unicode Common Locale Data Repository by cldr-quotes.pl.
+ *
+ * For terms of use, see http://www.unicode.org/copyright.html.
+ */
+
+/*
+ * Created on Mon Jul  8 20:11:49 2019 from CLDR data file cldr-common-35.1.zip.
+ *
+ * * * * * This file contains MACHINE-GENERATED DATA, do not edit! * * * * *
+ *
+ * (generated by intl/locale/cldr-quotes.pl)
+ */
+
+static const LangQuotesRec sLangQuotes[] = {
+  // clang-format off
+  { "af\0ak\0as\0asa\0az\0bem\0bez\0bn\0brx\0ccp\0ceb\0cgg\0chr\0cy\0da\0dav\0dje\0dz\0ebu\0ee\0en\0fil\0fo\0ga\0gd\0gl\0gu\0guz\0ha\0id\0ig\0jmc\0jv\0kam\0kde\0kea\0khq\0ki\0kln\0km\0kn\0kok\0ksb\0ku\0lg\0ln\0lo\0lrc\0lu\0luo\0lv\0mas\0mer\0mfe\0mgo\0mi\0ml\0mn\0mr\0ms\0mt\0my\0naq\0nd\0ne\0nus\0nyn\0or\0ps\0rof\0rwk\0saq\0sbp\0sd\0seh\0ses\0si\0so\0sw\0te\0teo\0th\0to\0tr\0tt\0twq\0tzm\0uz-Cyrl\0vai\0vun\0wo\0xog\0yo\0yue-Hans\0zh\0zu\0", { { 0x201c, 0x201d, 0x2018, 0x2019 } } },
+  { "agq\0ff\0", { { 0x201e, 0x201d, 0x201a, 0x2019 } } },
+  { "am\0az-Cyrl\0fa\0fr-CH\0gsw\0jgo\0kkj\0mzn\0", { { 0xab, 0xbb, 0x2039, 0x203a } } },
+  { "ar\0ur\0", { { 0x201d, 0x201c, 0x2019, 0x2018 } } },
+  { "ast\0bm\0ca\0dyo\0el\0es\0ewo\0it\0kab\0kk\0mg\0mua\0nnh\0pt-PT\0sg\0sq\0", { { 0xab, 0xbb, 0x201c, 0x201d } } },
+  { "bas\0be\0ky\0ru\0sah\0uk\0", { { 0xab, 0xbb, 0x201e, 0x201c } } },
+  { "bg\0lt\0", { { 0x201e, 0x201c, 0x201e, 0x201c } } },
+  { "br\0", { { 0x201c, 0x201d, 0xab, 0xbb } } },
+  { "bs-Cyrl\0cs\0de\0dsb\0et\0hr\0hsb\0is\0lb\0luy\0mk\0sk\0sl\0", { { 0x201e, 0x201c, 0x201a, 0x2018 } } },
+  { "bs\0", { { 0x201e, 0x201d, 0x2018, 0x2019 } } },
+  { "dua\0ksf\0nb\0nn\0rw\0", { { 0xab, 0xbb, 0x2018, 0x2019 } } },
+  { "es-419\0eu\0tk\0", { { 0x201c, 0x201d, 0x201c, 0x201d } } },
+  { "fi\0he\0lag\0rn\0sn\0sv\0", { { 0x201d, 0x201d, 0x2019, 0x2019 } } },
+  { "fr-CA\0", { { 0xab, 0xbb, 0x201d, 0x201c } } },
+  { "fr\0hy\0tg\0yav\0", { { 0xab, 0xbb, 0xab, 0xbb } } },
+  { "hu\0", { { 0x201e, 0x201d, 0xbb, 0xab } } },
+  { "ia\0nl\0ti-ER\0xh\0", { { 0x2018, 0x2019, 0x201c, 0x201d } } },
+  { "ja\0yue\0zh-Hant\0", { { 0x300c, 0x300d, 0x300e, 0x300f } } },
+  { "ka\0", { { 0x201e, 0x201c, 0xab, 0xbb } } },
+  { "nmg\0pl\0ro\0", { { 0x201e, 0x201d, 0xab, 0xbb } } },
+  { "shi\0zgh\0", { { 0xab, 0xbb, 0x201e, 0x201d } } },
+  { "sr\0", { { 0x201e, 0x201c, 0x2018, 0x2018 } } },
+  { "uz\0", { { 0x201c, 0x201d, 0x2019, 0x2018 } } },
+  // clang-format on
+};
diff --git a/intl/locale/cldr-quotes.pl b/intl/locale/cldr-quotes.pl
new file mode 100644
index 000000000000..33164bbadeff
--- /dev/null
+++ b/intl/locale/cldr-quotes.pl
@@ -0,0 +1,104 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Tool to generate the cldr-quotes.inc file, to be #include'd in Quotes.cpp
+# to provide locale-appropriate opening and closing quote marks.
+
+# To regenerate cldr-quotes.inc for a new CLDR release, download the data file
+# "cldr-common-##.zip" from http://unicode.org/Public/cldr/latest into the
+# current directory, update the $filename variable below accordingly, run
+#
+#   perl cldr-quotes.pl > cldr-quotes.inc
+#
+# then use `hg diff` to check that the result looks sane.
+
+use warnings;
+use strict;
+
+use Encode;
+use IO::Uncompress::Unzip;
+
+my $filename = 'cldr-common-35.1.zip';
+
+my (%langQuotes, %quoteLangs);
+
+my $zip = IO::Uncompress::Unzip->new($filename) ||
+  die "unzip failed: $IO::Uncompress::Unzip::UnzipError\n";
+my $status = 1;
+while ($status > 0) {
+  my $name = $zip->getHeaderInfo()->{Name};
+  if ($name =~ m@common/main/([A-Za-z0-9_]+)\.xml@) {
+    my $lang = $1;
+    $lang =~ s/_/-/;
+    while (<$zip>) {
+      $langQuotes{$lang}[0] = $1 if (m!<quotationStart>(.+)<!);
+      $langQuotes{$lang}[1] = $1 if (m!<quotationEnd>(.+)<!);
+      $langQuotes{$lang}[2] = $1 if (m!<alternateQuotationStart>(.+)<!);
+      $langQuotes{$lang}[3] = $1 if (m!<alternateQuotationEnd>(.+)<!);
+    }
+  }
+  $status = $zip->nextStream();
+}
+$zip->close;
+
+foreach my $lang (sort keys %langQuotes) {
+  # We don't actually want to emit anything for the root locale
+  next if $lang eq "root";
+
+  # Inherit any missing entries from the locale's parent
+  my $parent = $lang;
+  while ($parent =~ m/\-/) {
+    # Strip off a trailing subtag to find a parent locale code
+    $parent =~ s/\-[^-]+$//;
+    # Fill in any values available from the parent
+    for (my $i = 0; $i < 4; $i++) {
+      $langQuotes{$lang}[$i] = $langQuotes{$parent}[$i] unless $langQuotes{$lang}[$i];
+    }
+  }
+
+  # Anything still missing is copied from the root locale
+  for (my $i = 0; $i < 4; $i++) {
+    $langQuotes{$lang}[$i] = $langQuotes{"root"}[$i] unless $langQuotes{$lang}[$i];
+  }
+
+  # If the locale ends up the same as its parent, skip
+  next if ($parent ne $lang) && (exists $langQuotes{$parent}) &&
+    (join(",", @{$langQuotes{$lang}}) eq join(",", @{$langQuotes{$parent}}));
+
+  # Create a string with the C source form for the array of 4 quote characters
+  my $quoteChars = join(", ", map { sprintf("0x%x", ord Encode::decode("UTF-8", $_)) } @{$langQuotes{$lang}});
+
+  # Record this locale in the list of those which use this particular set of quotes
+  $quoteLangs{$quoteChars} = [] unless exists $quoteLangs{$quoteChars};
+  push $quoteLangs{$quoteChars}, $lang;
+}
+
+# Output each unique list of quotes, with the string of associated locales
+my $timestamp = gmtime();
+print <<__EOT__;
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Derived from the Unicode Common Locale Data Repository by cldr-quotes.pl.
+ *
+ * For terms of use, see http://www.unicode.org/copyright.html.
+ */
+
+/*
+ * Created on $timestamp from CLDR data file $filename.
+ *
+ * * * * * This file contains MACHINE-GENERATED DATA, do not edit! * * * * *
+ *
+ * (generated by intl/locale/cldr-quotes.pl)
+ */
+
+__EOT__
+
+print "static const LangQuotesRec sLangQuotes[] = {\n";
+print "  // clang-format off\n";
+print sort map { sprintf("  { \"%s\\0\", { { %s } } },\n", join("\\0", sort @{$quoteLangs{$_}}), $_) } (keys %quoteLangs);
+print "  // clang-format on\n";
+print "};\n";
diff --git a/intl/locale/moz.build b/intl/locale/moz.build
index fe97934a33af..8587ed4bfe0c 100644
--- a/intl/locale/moz.build
+++ b/intl/locale/moz.build
@@ -36,6 +36,7 @@ EXPORTS.mozilla.intl += [
     'LocaleService.h',
     'MozLocale.h',
     'OSPreferences.h',
+    'Quotes.h',
 ]
 
 UNIFIED_SOURCES += [
@@ -47,6 +48,7 @@ UNIFIED_SOURCES += [
     'nsLanguageAtomService.cpp',
     'nsUConvPropertySearch.cpp',
     'OSPreferences.cpp',
+    'Quotes.cpp',
 ]
 
 EXTRA_JS_MODULES += [