diff --git a/django/core/management/base.py b/django/core/management/base.py
index 68bcb188e56..869a11bce93 100644
--- a/django/core/management/base.py
+++ b/django/core/management/base.py
@@ -18,6 +18,7 @@ import django
 from django.core import checks
 from django.core.exceptions import ImproperlyConfigured
 from django.core.management.color import color_style, no_style
+from django.db import connections
 from django.utils.deprecation import RemovedInDjango19Warning, RemovedInDjango20Warning
 from django.utils.encoding import force_str
 
@@ -398,6 +399,8 @@ class BaseCommand(object):
             else:
                 self.stderr.write('%s: %s' % (e.__class__.__name__, e))
             sys.exit(1)
+        finally:
+            connections.close_all()
 
     def execute(self, *args, **options):
         """
diff --git a/django/db/utils.py b/django/db/utils.py
index acb90c0a1ad..a355bbe466d 100644
--- a/django/db/utils.py
+++ b/django/db/utils.py
@@ -252,6 +252,14 @@ class ConnectionHandler(object):
     def all(self):
         return [self[alias] for alias in self]
 
+    def close_all(self):
+        for alias in self:
+            try:
+                connection = getattr(self._connections, alias)
+            except AttributeError:
+                continue
+            connection.close()
+
 
 class ConnectionRouter(object):
     def __init__(self, routers=None):
diff --git a/docs/releases/1.8.txt b/docs/releases/1.8.txt
index 7379e1da8f6..507aed65844 100644
--- a/docs/releases/1.8.txt
+++ b/docs/releases/1.8.txt
@@ -352,6 +352,9 @@ Logging
 Management Commands
 ^^^^^^^^^^^^^^^^^^^
 
+* Database connections are now always closed after a management command called
+  from the command line has finished doing its job.
+
 * :djadmin:`dumpdata` now has the option :djadminopt:`--output` which allows
   specifying the file to which the serialized data is written.
 
diff --git a/tests/admin_scripts/tests.py b/tests/admin_scripts/tests.py
index 518c83b4bef..086e5365a18 100644
--- a/tests/admin_scripts/tests.py
+++ b/tests/admin_scripts/tests.py
@@ -25,7 +25,7 @@ from django.core.management import BaseCommand, CommandError, call_command, colo
 from django.utils.encoding import force_text
 from django.utils._os import npath, upath
 from django.utils.six import StringIO
-from django.test import LiveServerTestCase, TestCase, override_settings
+from django.test import LiveServerTestCase, TestCase, mock, override_settings
 from django.test.runner import DiscoverRunner
 
 
@@ -1581,6 +1581,18 @@ class CommandTypes(AdminScriptTestCase):
         with self.assertRaises(SystemExit):
             command.run_from_argv(['', ''])
 
+    def test_run_from_argv_closes_connections(self):
+        """
+        A command called from the command line should close connections after
+        being executed (#21255).
+        """
+        command = BaseCommand(stderr=StringIO())
+        command.handle = lambda *args, **kwargs: args
+        with mock.patch('django.core.management.base.connections') as mock_connections:
+            command.run_from_argv(['', ''])
+        # Test connections have been closed
+        self.assertTrue(mock_connections.close_all.called)
+
     def test_noargs(self):
         "NoArg Commands can be executed"
         args = ['noargs_command']