--- a/python/mach/mach/main.py
+++ b/python/mach/mach/main.py
@@ -15,20 +15,22 @@ import sys
 from mozbuild.base import BuildConfig
 from mozbuild.config import ConfigSettings
 from mozbuild.logger import LoggingManager
 
 # Import sub-command modules
 # TODO Bug 794509 do this via auto-discovery. Update README once this is
 # done.
 from mach.settings import Settings
+from mach.testing import Testing
 
 # Classes inheriting from ArgumentProvider that provide commands.
 HANDLERS = [
     Settings,
+    Testing,
 ]
 
 # Classes inheriting from ConfigProvider that provide settings.
 # TODO this should come from auto-discovery somehow.
 SETTINGS_PROVIDERS = [
     BuildConfig,
 ]
 
@@ -51,16 +53,17 @@ class Mach(object):
     USAGE = """%(prog)s subcommand [arguments]
 
 mach provides an interface to performing common developer tasks. You specify
 an action/sub-command and it performs it.
 
 Some common actions are:
 
     %(prog)s help      Show full help, including the list of all commands.
+    %(prog)s test      Run tests.
 
 To see more help for a specific action, run:
 
   %(prog)s <command> --help
 """
 
     def __init__(self, cwd):
         assert os.path.isdir(cwd)

new file mode 100644
--- /dev/null
+++ b/python/mach/mach/testing.py
@@ -0,0 +1,78 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import unicode_literals
+
+from mach.base import ArgumentProvider
+from mozbuild.base import MozbuildObject
+
+
+generic_help = 'Test to run. Can be specified as a single JS file, a ' +\
+'directory, or omitted. If omitted, the entire test suite is executed.'
+
+
+class Testing(MozbuildObject, ArgumentProvider):
+    """Provides commands for running tests."""
+
+    def run_suite(self, suite):
+        from mozbuild.testing.suite import Suite
+
+        s = self._spawn(Suite)
+        s.run_suite(suite)
+
+    def run_mochitest(self, test_file, flavor):
+        from mozbuild.testing.mochitest import MochitestRunner
+
+        mochitest = self._spawn(MochitestRunner)
+        mochitest.run_mochitest_test(test_file, flavor)
+
+    def run_xpcshell_test(self, **params):
+        from mozbuild.testing.xpcshell import XPCShellRunner
+
+        xpcshell = self._spawn(XPCShellRunner)
+        xpcshell.run_test(**params)
+
+    @staticmethod
+    def populate_argparse(parser):
+        # Whole suites.
+        group = parser.add_parser('test', help="Perform tests.")
+
+        suites = set(['xpcshell', 'mochitest-plain', 'mochitest-chrome',
+            'mochitest-browser', 'all'])
+
+        group.add_argument('suite', default='all', choices=suites, nargs='?',
+            help="Test suite to run.")
+
+        group.set_defaults(cls=Testing, method='run_suite', suite='all')
+
+        mochitest_plain = parser.add_parser('mochitest-plain',
+            help='Run a plain mochitest.')
+        mochitest_plain.add_argument('test_file', default='all', nargs='?',
+            metavar='TEST', help=generic_help)
+        mochitest_plain.set_defaults(cls=Testing, method='run_mochitest',
+            flavor='plain')
+
+        mochitest_chrome = parser.add_parser('mochitest-chrome',
+            help='Run a chrome mochitest.')
+        mochitest_chrome.add_argument('test_file', default='all', nargs='?',
+            metavar='TEST', help=generic_help)
+        mochitest_chrome.set_defaults(cls=Testing, method='run_mochitest',
+            flavor='chrome')
+
+        mochitest_browser = parser.add_parser('mochitest-browser',
+            help='Run a mochitest with browser chrome.')
+        mochitest_browser.add_argument('test_file', default='all', nargs='?',
+            metavar='TEST', help=generic_help)
+        mochitest_browser.set_defaults(cls=Testing, method='run_mochitest',
+            flavor='browser')
+
+        xpcshell = parser.add_parser('xpcshell-test',
+            help="Run an individual xpcshell test.")
+
+        xpcshell.add_argument('test_file', default='all', nargs='?',
+            metavar='TEST', help=generic_help)
+        xpcshell.add_argument('--debug', '-d', action='store_true',
+            help='Run test in debugger.')
+
+        xpcshell.set_defaults(cls=Testing, method='run_xpcshell_test')