diff --git a/django/utils/html.py b/django/utils/html.py
index 2687eb5232..4f74a7492c 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -17,6 +17,7 @@ TRAILING_PUNCTUATION = ['.', ',', ')', '>', '\n', '>']
 DOTS = [u'·', u'*', u'\u2022', u'•', u'•', u'•']
 
 unencoded_ampersands_re = re.compile(r'&(?!(\w+|#\d+);)')
+unquoted_percents_re = re.compile(r'%(?![0-9A-Fa-f]{2})')
 word_split_re = re.compile(r'(\s+)')
 punctuation_re = re.compile('^(?P<lead>(?:%s)*)(?P<middle>.*?)(?P<trail>(?:%s)*)$' % \
     ('|'.join([re.escape(x) for x in LEADING_PUNCTUATION]),
@@ -100,6 +101,15 @@ def fix_ampersands(value):
     return unencoded_ampersands_re.sub('&amp;', force_unicode(value))
 fix_ampersands = allow_lazy(fix_ampersands, unicode)
 
+def smart_urlquote(url):
+    """Quotes an URL if it isn't already quoted."""
+    # An URL is considered unquoted if it contains no % character, or if it
+    # contains a % not followed by two hexadecimal digits. See #9655.
+    if '%' not in url or unquoted_percents_re.search(url):
+        # See http://bugs.python.org/issue2637
+        return urlquote(url, safe='!*\'();:@&=+$,/?#[]~')
+    return url
+
 def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
     """
     Converts any URLs in text into clickable links.
@@ -130,11 +140,11 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
             # Make URL we want to point to.
             url = None
             if middle.startswith('http://') or middle.startswith('https://'):
-                url = urlquote(middle, safe='/&=:;#?+*')
+                url = smart_urlquote(middle)
             elif middle.startswith('www.') or ('@' not in middle and \
                     middle and middle[0] in string.ascii_letters + string.digits and \
                     (middle.endswith('.org') or middle.endswith('.net') or middle.endswith('.com'))):
-                url = urlquote('http://%s' % middle, safe='/&=:;#?+*')
+                url = smart_urlquote('http://%s' % middle)
             elif '@' in middle and not ':' in middle and simple_email_re.match(middle):
                 url = 'mailto:%s' % middle
                 nofollow_attr = ''
diff --git a/docs/releases/1.4.txt b/docs/releases/1.4.txt
index de7afc83c3..9f9ce7fb59 100644
--- a/docs/releases/1.4.txt
+++ b/docs/releases/1.4.txt
@@ -1044,6 +1044,15 @@ Now, the flags are keyword arguments of :meth:`@register.filter
 
 See :ref:`filters and auto-escaping <filters-auto-escaping>` for more information.
 
+The :tfilter:`urlize` filter no longer escapes every URL
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When an URL contains a ``%xx`` sequence, where ``xx`` are two hexadecimal
+digits, :tfilter:`urlize` assumes that the URL is already escaped, and doesn't
+apply URL escaping again. This is wrong for URLs whose unquoted form contains
+a ``%xx`` sequence, but such URLs are very unlikely to happen in the wild,
+since they would confuse browsers too.
+
 Session cookies now have the ``httponly`` flag by default
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/tests/regressiontests/defaultfilters/tests.py b/tests/regressiontests/defaultfilters/tests.py
index 5e8c8f1538..00518344a3 100644
--- a/tests/regressiontests/defaultfilters/tests.py
+++ b/tests/regressiontests/defaultfilters/tests.py
@@ -238,6 +238,19 @@ class DefaultFiltersTests(TestCase):
         # Check urlize with https addresses
         self.assertEqual(urlize('https://google.com'),
             u'<a href="https://google.com" rel="nofollow">https://google.com</a>')
+        # Check urlize doesn't overquote already quoted urls - see #9655
+        self.assertEqual(urlize('http://hi.baidu.com/%D6%D8%D0%C2%BF'),
+            u'<a href="http://hi.baidu.com/%D6%D8%D0%C2%BF" rel="nofollow">'
+            u'http://hi.baidu.com/%D6%D8%D0%C2%BF</a>')
+        self.assertEqual(urlize('www.mystore.com/30%OffCoupons!'),
+            u'<a href="http://www.mystore.com/30%25OffCoupons!" rel="nofollow">'
+            u'www.mystore.com/30%OffCoupons!</a>')
+        self.assertEqual(urlize('http://en.wikipedia.org/wiki/Caf%C3%A9'),
+            u'<a href="http://en.wikipedia.org/wiki/Caf%C3%A9" rel="nofollow">'
+            u'http://en.wikipedia.org/wiki/Caf%C3%A9</a>')
+        self.assertEqual(urlize('http://en.wikipedia.org/wiki/Café'),
+            u'<a href="http://en.wikipedia.org/wiki/Caf%C3%A9" rel="nofollow">'
+            u'http://en.wikipedia.org/wiki/Café</a>')
 
     def test_wordcount(self):
         self.assertEqual(wordcount(''), 0)