diff -r acdebfbfbdcf Doc/library/unittest.rst
--- a/Doc/library/unittest.rst	Tue Oct 06 13:29:56 2015 -0400
+++ b/Doc/library/unittest.rst	Wed Oct 07 15:07:34 2015 +0000
@@ -218,6 +218,10 @@
 
    Show local variables in tracebacks.
 
+.. cmdoption:: -g, --garbage-collected
+
+   Run garbage collection after each test.
+
 .. versionadded:: 3.2
    The command-line options ``-b``, ``-c`` and ``-f`` were added.
 
diff -r acdebfbfbdcf Lib/unittest/main.py
--- a/Lib/unittest/main.py	Tue Oct 06 13:29:56 2015 -0400
+++ b/Lib/unittest/main.py	Wed Oct 07 15:07:34 2015 +0000
@@ -52,13 +52,15 @@
     # defaults for testing
     module=None
     verbosity = 1
+    gc_enabled = False
     failfast = catchbreak = buffer = progName = warnings = None
     _discovery_parser = None
 
     def __init__(self, module='__main__', defaultTest=None, argv=None,
                     testRunner=None, testLoader=loader.defaultTestLoader,
                     exit=True, verbosity=1, failfast=None, catchbreak=None,
-                    buffer=None, warnings=None, *, tb_locals=False):
+                    buffer=None, warnings=None, *, tb_locals=False,
+                    gc_enabled=False):
         if isinstance(module, str):
             self.module = __import__(module)
             for part in module.split('.')[1:]:
@@ -74,6 +76,7 @@
         self.verbosity = verbosity
         self.buffer = buffer
         self.tb_locals = tb_locals
+        self.gc_enabled = gc_enabled
         if warnings is None and not sys.warnoptions:
             # even if DeprecationWarnings are ignored by default
             # print them anyway unless other warnings settings are
@@ -163,6 +166,9 @@
         parser.add_argument('--locals', dest='tb_locals',
                             action='store_true',
                             help='Show local variables in tracebacks')
+        parser.add_argument('-g', '--garbage-collected', dest='gc_enabled',
+                            action='store_true',
+                            help='Run garbage collection after each test')
         if self.failfast is None:
             parser.add_argument('-f', '--failfast', dest='failfast',
                                 action='store_true',
@@ -239,13 +245,15 @@
                                                  failfast=self.failfast,
                                                  buffer=self.buffer,
                                                  warnings=self.warnings,
-                                                 tb_locals=self.tb_locals)
+                                                 tb_locals=self.tb_locals,
+                                                 gc_enabled=self.gc_enabled)
                 except TypeError:
                     # didn't accept the tb_locals argument
                     testRunner = self.testRunner(verbosity=self.verbosity,
                                                  failfast=self.failfast,
                                                  buffer=self.buffer,
-                                                 warnings=self.warnings)
+                                                 warnings=self.warnings,
+                                                 gc_enabled=self.gc_enabled)
             except TypeError:
                 # didn't accept the verbosity, buffer or failfast arguments
                 testRunner = self.testRunner()
diff -r acdebfbfbdcf Lib/unittest/result.py
--- a/Lib/unittest/result.py	Tue Oct 06 13:29:56 2015 -0400
+++ b/Lib/unittest/result.py	Wed Oct 07 15:07:34 2015 +0000
@@ -1,5 +1,6 @@
 """Test result object"""
 
+import gc
 import io
 import sys
 import traceback
@@ -35,10 +36,12 @@
     _previousTestClass = None
     _testRunEntered = False
     _moduleSetUpFailed = False
-    def __init__(self, stream=None, descriptions=None, verbosity=None):
+    def __init__(self, stream=None, descriptions=None,
+                 verbosity=None, gc_enabled=False):
         self.failfast = False
         self.failures = []
         self.errors = []
+        self.gc_enabled=gc_enabled
         self.testsRun = 0
         self.skipped = []
         self.expectedFailures = []
@@ -79,6 +82,8 @@
         """Called when the given test has been run"""
         self._restoreStdout()
         self._mirrorOutput = False
+        if self.gc_enabled:
+            gc.collect()
 
     def _restoreStdout(self):
         if self.buffer:
diff -r acdebfbfbdcf Lib/unittest/runner.py
--- a/Lib/unittest/runner.py	Tue Oct 06 13:29:56 2015 -0400
+++ b/Lib/unittest/runner.py	Wed Oct 07 15:07:34 2015 +0000
@@ -34,8 +34,9 @@
     separator1 = '=' * 70
     separator2 = '-' * 70
 
-    def __init__(self, stream, descriptions, verbosity):
-        super(TextTestResult, self).__init__(stream, descriptions, verbosity)
+    def __init__(self, stream, descriptions, verbosity, gc_enabled):
+        super(TextTestResult, self).__init__(stream, descriptions,
+                                             verbosity, gc_enabled)
         self.stream = stream
         self.showAll = verbosity > 1
         self.dots = verbosity == 1
@@ -127,7 +128,7 @@
 
     def __init__(self, stream=None, descriptions=True, verbosity=1,
                  failfast=False, buffer=False, resultclass=None, warnings=None,
-                 *, tb_locals=False):
+                 *, tb_locals=False, gc_enabled=False):
         """Construct a TextTestRunner.
 
         Subclasses should accept **kwargs to ensure compatibility as the
@@ -139,6 +140,7 @@
         self.descriptions = descriptions
         self.verbosity = verbosity
         self.failfast = failfast
+        self.gc_enabled = gc_enabled
         self.buffer = buffer
         self.tb_locals = tb_locals
         self.warnings = warnings
@@ -146,7 +148,8 @@
             self.resultclass = resultclass
 
     def _makeResult(self):
-        return self.resultclass(self.stream, self.descriptions, self.verbosity)
+        return self.resultclass(self.stream, self.descriptions,
+                                self.verbosity, self.gc_enabled)
 
     def run(self, test):
         "Run the given test case or test suite."