diff --git a/LICENSE.rst b/LICENSE.rst
new file mode 100644
index 0000000..475ec73
--- /dev/null
+++ b/LICENSE.rst
@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2017, Smithsonian Astrophysical Observatory
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the copyright holder nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Ska/Shell/__init__.py b/Ska/Shell/__init__.py
index 8532c29..8f38c5c 100644
--- a/Ska/Shell/__init__.py
+++ b/Ska/Shell/__init__.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from .shell import *
 
 __version__ = '3.3.2'
diff --git a/Ska/Shell/shell.py b/Ska/Shell/shell.py
index 3a846a3..dae2b2e 100644
--- a/Ska/Shell/shell.py
+++ b/Ska/Shell/shell.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """Utilities to run subprocesses"""
 
 import re
diff --git a/Ska/Shell/tests/test_shell.py b/Ska/Shell/tests/test_shell.py
index cd27210..db0a002 100644
--- a/Ska/Shell/tests/test_shell.py
+++ b/Ska/Shell/tests/test_shell.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import os
 import pytest
 from six.moves import cStringIO as StringIO
diff --git a/Ska/__init__.py b/Ska/__init__.py
index bb61062..46d8fff 100644
--- a/Ska/__init__.py
+++ b/Ska/__init__.py
@@ -1,2 +1,3 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import pkgutil
 __path__ = pkgutil.extend_path(__path__, __name__)
diff --git a/doc/conf.py b/doc/conf.py
index 72d7f0a..16bb0bc 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -10,6 +10,7 @@
 #
 # All configuration values have a default; values that are commented out
 # serve to show the default.
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 
 import sys, os
 
diff --git a/setup.py b/setup.py
index a15dc1c..9337a22 100755
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from setuptools import setup
 
 from Ska.Shell import __version__