diff --git a/.travis.yml b/.travis.yml
index 5bfe15b..79631b8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,8 +23,6 @@
           env: TOXENV=py26
         - python: 2.7
           env: TOXENV=py27
-        - python: 3.3
-          env: TOXENV=py33
         - python: 3.4
           env: TOXENV=py34
         - python: 3.5
@@ -57,10 +55,6 @@
         - language: generic
           os: osx
           osx_image: xcode8.3
-          env: TOXENV=py33 CRYPTOGRAPHY_SUPPRESS_LINK_FLAGS=1
-        - language: generic
-          os: osx
-          osx_image: xcode8.3
           env: TOXENV=py34 CRYPTOGRAPHY_SUPPRESS_LINK_FLAGS=1
         - language: generic
           os: osx
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 88c945f..020defa 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,6 +6,7 @@
 
 .. note:: This version is not yet released and is under active development.
 
+* **BACKWARDS INCOMPATIBLE:** Support for Python 3.3 has been dropped.
 * Deprecated the use of ``signer`` on
   :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`,
   :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey`,
diff --git a/Jenkinsfile b/Jenkinsfile
index 5440093..50f53a2 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -5,11 +5,11 @@
 def configs = [
     [
         label: 'windows',
-        toxenvs: ['py26', 'py27', 'py33', 'py34', 'py35', 'py36'],
+        toxenvs: ['py26', 'py27', 'py34', 'py35', 'py36'],
     ],
     [
         label: 'windows64',
-        toxenvs: ['py26', 'py27', 'py33', 'py34', 'py35', 'py36'],
+        toxenvs: ['py26', 'py27', 'py34', 'py35', 'py36'],
     ],
     [
         label: 'freebsd11',
@@ -199,7 +199,6 @@
                         def pythonPath = [
                             py26: "C:\\Python26\\python.exe",
                             py27: "C:\\Python27\\python.exe",
-                            py33: "C:\\Python33\\python.exe",
                             py34: "C:\\Python34\\python.exe",
                             py35: "C:\\Python35\\python.exe",
                             py36: "C:\\Python36\\python.exe"
diff --git a/README.rst b/README.rst
index e21fe48..350dc72 100644
--- a/README.rst
+++ b/README.rst
@@ -18,7 +18,7 @@
 
 ``cryptography`` is a package which provides cryptographic recipes and
 primitives to Python developers.  Our goal is for it to be your "cryptographic
-standard library". It supports Python 2.6-2.7, Python 3.3+, and PyPy 5.3+.
+standard library". It supports Python 2.6-2.7, Python 3.4+, and PyPy 5.3+.
 
 ``cryptography`` includes both high level recipes and low level interfaces to
 common cryptographic algorithms such as symmetric ciphers, message digests, and
diff --git a/docs/installation.rst b/docs/installation.rst
index a18014c..0fa986a 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -10,7 +10,7 @@
 Supported platforms
 -------------------
 
-Currently we test ``cryptography`` on Python 2.6, 2.7, 3.3, 3.4, 3.5, 3.6, and
+Currently we test ``cryptography`` on Python 2.6, 2.7, 3.4, 3.5, 3.6, and
 PyPy 5.3+ on these operating systems.
 
 * x86-64 CentOS 7.x
@@ -24,8 +24,6 @@
     Python 2.6 is no longer supported by the Python core team. A future version
     of cryptography will drop support for this version.
 
-    Python 3.3 support will be removed in the next cryptography release.
-
 We test compiling with ``clang`` as well as ``gcc`` and use the following
 OpenSSL releases:
 
diff --git a/setup.py b/setup.py
index 5bc4b50..8bb591f 100644
--- a/setup.py
+++ b/setup.py
@@ -275,7 +275,6 @@
         "Programming Language :: Python :: 2.6",
         "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.3",
         "Programming Language :: Python :: 3.4",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
diff --git a/src/cryptography/__init__.py b/src/cryptography/__init__.py
index a0c8d46..940c66b 100644
--- a/src/cryptography/__init__.py
+++ b/src/cryptography/__init__.py
@@ -25,9 +25,3 @@
         "support for Python 2.6",
         DeprecationWarning
     )
-if sys.version_info[:2] == (3, 3):
-    warnings.warn(
-        "Python 3.3 support will be dropped in the next release of"
-        "cryptography. Please upgrade your Python.",
-        DeprecationWarning,
-    )