diff -r f051a545a38a Lib/logging/__init__.py
--- a/Lib/logging/__init__.py	Mon Jan 13 11:25:14 2014 -0800
+++ b/Lib/logging/__init__.py	Mon Jan 13 11:36:12 2014 -0800
@@ -313,6 +313,33 @@
             msg = msg % self.args
         return msg
 
+
+class StrFormatLogRecord(LogRecord):
+    def getMessage(self):
+        """
+        Return the message for this LogRecord.
+
+        Return the message for this LogRecord after merging any user-supplied
+        arguments with the message.
+        """
+        msg = str(self.msg)
+        if self.args:
+            msg = msg.format(*self.args)
+        return msg
+
+class StringTemplateLogRecord(LogRecord):
+    def getMessage(self):
+        """
+        Return the message for this LogRecord.
+
+        Return the message for this LogRecord after merging any user-supplied
+        arguments with the message.
+        """
+        msg = str(self.msg)
+        if self.args:
+            tpl = Template(msg)
+            msg = tpl.substitute(**self.args)
+        return msg
 #
 #   Determine which class to use when instantiating log records.
 #
@@ -391,9 +418,9 @@
         return self._tpl.substitute(**record.__dict__)
 
 _STYLES = {
-    '%': PercentStyle,
-    '{': StrFormatStyle,
-    '$': StringTemplateStyle
+    '%': (PercentStyle, LogRecord),
+    '{': (StrFormatStyle, StrFormatLogRecord),
+    '$': (StringTemplateStyle, StringTemplateLogRecord)
 }
 
 class Formatter(object):
@@ -458,7 +485,7 @@
         if style not in _STYLES:
             raise ValueError('Style must be one of: %s' % ','.join(
                              _STYLES.keys()))
-        self._style = _STYLES[style](fmt)
+        self._style = _STYLES[style][0](fmt)
         self._fmt = self._style._fmt
         self.datefmt = datefmt
 
@@ -1724,6 +1751,7 @@
             if fs is None and style == "%":
                 fs = BASIC_FORMAT
             fmt = Formatter(fs, dfs, style)
+            setLogRecordFactory(_STYLES[style][1])
             for h in handlers:
                 if h.formatter is None:
                     h.setFormatter(fmt)
diff -r f051a545a38a Lib/test/test_logging.py
--- a/Lib/test/test_logging.py	Mon Jan 13 11:25:14 2014 -0800
+++ b/Lib/test/test_logging.py	Mon Jan 13 11:36:12 2014 -0800
@@ -3517,6 +3517,22 @@
         # level is not explicitly set
         self.assertEqual(logging.root.level, self.original_logging_level)
 
+    def test_percentstyle(self):
+        with captured_stdout() as output:
+            logging.basicConfig(stream=sys.stdout, style="%")
+            logging.error("Log an error")
+            sys.stdout.seek(0)
+            self.assertEqual(output.getvalue(),
+                "ERROR:root:Log an error\n")
+
+    def test_percentstyle(self):
+        with captured_stdout() as output:
+            logging.basicConfig(stream=sys.stdout, style="%")
+            logging.error("Log %s", "an error")
+            sys.stdout.seek(0)
+            self.assertEqual(output.getvalue(),
+                "ERROR:root:Log an error\n")
+
     def test_strformatstyle(self):
         with captured_stdout() as output:
             logging.basicConfig(stream=sys.stdout, style="{")
@@ -3525,6 +3541,14 @@
             self.assertEqual(output.getvalue(),
                 "ERROR:root:Log an error\n")
 
+    def test_strformatstyle2(self):
+        with captured_stdout() as output:
+            logging.basicConfig(stream=sys.stdout, style="{")
+            logging.error("Log {}", "an error")
+            sys.stdout.seek(0)
+            self.assertEqual(output.getvalue(),
+                "ERROR:root:Log an error\n")
+
     def test_stringtemplatestyle(self):
         with captured_stdout() as output:
             logging.basicConfig(stream=sys.stdout, style="$")
@@ -3533,6 +3557,14 @@
             self.assertEqual(output.getvalue(),
                 "ERROR:root:Log an error\n")
 
+    def test_stringtemplatestyle2(self):
+        with captured_stdout() as output:
+            logging.basicConfig(stream=sys.stdout, style="$")
+            logging.error("Log $foo", {"foo":"an error"})
+            sys.stdout.seek(0)
+            self.assertEqual(output.getvalue(),
+                "ERROR:root:Log an error\n")
+
     def test_filename(self):
 
         def cleanup(h1, h2, fn):