diff -r b04560c3ce69 Doc/library/csv.rst
--- a/Doc/library/csv.rst	Wed Aug 03 22:02:42 2016 -0700
+++ b/Doc/library/csv.rst	Sat Aug 27 01:26:22 2016 +0800
@@ -150,18 +150,25 @@
                       dialect='excel', *args, **kwds)
 
    Create an object which operates like a regular reader but maps the
-   information read into a dict whose keys are given by the optional
-   *fieldnames* parameter.  The *fieldnames* parameter is a :mod:`sequence
-   <collections.abc>` whose elements are associated with the fields of the
+   information read into an :mod:`OrderedDict <collections.OrderedDict>`
+   whose keys are given by the optional *fieldnames* parameter.
+   The *fieldnames* parameter is a :mod:`sequence <collections.abc>`
+   whose elements are associated with the fields of the
    input data in order. These elements become the keys of the resulting
-   dictionary.  If the *fieldnames* parameter is omitted, the values in the
-   first row of the *csvfile* will be used as the fieldnames.  If the row read
-   has more fields than the fieldnames sequence, the remaining data is added as
-   a sequence keyed by the value of *restkey*.  If the row read has fewer
+   :mod:`OrderedDict <collections.OrderedDict>`.  If the *fieldnames* parameter
+   is omitted, the values in the first row of the *csvfile* will be used as the
+   fieldnames.  If the row read has more fields than the fieldnames sequence,
+   the remaining data is added as a sequence keyed by the value of *restkey*.
+   However the fieldnames are determined they retain their ordering in the
+   :mod:`OrderedDict <collections.OrderedDict>`. If the row read has fewer
    fields than the fieldnames sequence, the remaining keys take the value of
    the optional *restval* parameter.  Any other optional or keyword arguments
    are passed to the underlying :class:`reader` instance.
 
+   .. versionchanged:: 3.6
+      Returned rows are now of type :class:`OrderedDict` rather than a
+      simple dictionary.
+
    A short usage example::
 
        >>> import csv
diff -r b04560c3ce69 Lib/csv.py
--- a/Lib/csv.py	Wed Aug 03 22:02:42 2016 -0700
+++ b/Lib/csv.py	Sat Aug 27 01:26:22 2016 +0800
@@ -11,6 +11,7 @@
                  __doc__
 from _csv import Dialect as _Dialect
 
+from collections import OrderedDict
 from io import StringIO
 
 __all__ = ["QUOTE_MINIMAL", "QUOTE_ALL", "QUOTE_NONNUMERIC", "QUOTE_NONE",
@@ -116,7 +117,7 @@
         # values
         while row == []:
             row = next(self.reader)
-        d = dict(zip(self.fieldnames, row))
+        d = OrderedDict(zip(self.fieldnames, row))
         lf = len(self.fieldnames)
         lr = len(row)
         if lf < lr:
diff -r b04560c3ce69 Lib/test/test_csv.py
--- a/Lib/test/test_csv.py	Wed Aug 03 22:02:42 2016 -0700
+++ b/Lib/test/test_csv.py	Sat Aug 27 01:26:22 2016 +0800
@@ -10,6 +10,7 @@
 import gc
 import pickle
 from test import support
+from itertools import permutations
 
 class Test_Csv(unittest.TestCase):
     """
@@ -1092,6 +1093,20 @@
             fileobj.seek(0)
             self.assertEqual(fileobj.read(), expected)
 
+class KeyOrderingTest(unittest.TestCase):
+    def test_ordering(self):
+        resultset = set()
+        for keys in permutations("abcde"):
+            with TemporaryFile('w+', newline='', encoding="utf-8") as fileobject:
+                dw = csv.DictWriter(fileobject, keys)
+                dw.writeheader()
+                fileobject.seek(0)
+                dr = csv.DictReader(fileobject)
+                kt = tuple(dr.fieldnames)
+                self.assertEqual(keys, kt)
+                resultset.add(kt)
+        # Final sanity check: were all permutations unique?
+        self.assertEqual(len(resultset), 120, "Key ordering: some key permutations not collected (expected 120)")                         
 
 class MiscTestCase(unittest.TestCase):
     def test__all__(self):