--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -1255,12 +1255,27 @@ class Query(object):
         self._offset = offset
 
     @_generative(_no_statement_condition)
-    def distinct(self):
+    @util.accepts_a_list_as_starargs(list_deprecation='pending')
+    def distinct(self, *criterion):
         """Apply a ``DISTINCT`` to the query and return the newly resulting
         ``Query``.
 
+        Can accept list of expressions to construct postgresql DISTINCT ON clause
+        or None to remove it from query.
+
         """
-        self._distinct = True
+
+        if not criterion:
+            self._distinct = True
+        if len(criterion) == 1 and criterion[0] is None:
+            self._distinct = False
+        else:
+            criterion = [self._adapt_clause(expression._literal_as_text(o), True, True) for o in criterion]
+
+            if not isinstance(self._distinct, bool):
+                self._distinct += criterion
+            else:
+                self._distinct = criterion
 
     def all(self):
         """Return the results represented by this ``Query`` as a list.