diff --git a/.travis.yml b/.travis.yml
index 70bafca7a..d03d6f872 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,8 +24,6 @@ matrix:
     env: TOXENV=py26
   - python: "2.7"
     env: TOXENV=py27
-  - python: "3.3"
-    env: TOXENV=py33
   - python: "3.4"
     env: TOXENV=py34
   - python: "3.5"
@@ -39,8 +37,6 @@ matrix:
     env: TOXENV=py26-cryptographyMaster
   - python: "2.7"
     env: TOXENV=py27-cryptographyMaster
-  - python: "3.3"
-    env: TOXENV=py33-cryptographyMaster
   - python: "3.4"
     env: TOXENV=py34-cryptographyMaster
   - python: "3.5"
@@ -54,8 +50,6 @@ matrix:
     env: TOXENV=py26-cryptographyMinimum
   - python: "2.7"
     env: TOXENV=py27-cryptographyMinimum
-  - python: "3.3"
-    env: TOXENV=py33-cryptographyMinimum
   - python: "3.4"
     env: TOXENV=py34-cryptographyMinimum
   - python: "3.5"
@@ -90,7 +84,6 @@ matrix:
   allow_failures:
   - env: TOXENV=py26-cryptographyMaster
   - env: TOXENV=py27-cryptographyMaster
-  - env: TOXENV=py33-cryptographyMaster
   - env: TOXENV=py34-cryptographyMaster
   - env: TOXENV=py35-cryptographyMaster
   - env: TOXENV=py36-cryptographyMaster
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index af2f26d43..7b2f4db11 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -12,7 +12,8 @@ The third digit is only for regressions.
 Backward-incompatible changes:
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-*none*
+- Dropped support for Python 3.3.
+  `#677 <https://github.com/pyca/pyopenssl/pull/677>`_
 
 
 Deprecations:
diff --git a/setup.py b/setup.py
index afd5fa000..13188ef4c 100755
--- a/setup.py
+++ b/setup.py
@@ -80,7 +80,6 @@ def find_meta(meta):
             '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/tox.ini b/tox.ini
index 877146b4c..a16e69015 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = {pypy,py26,py27,py33,py34,py35,py36}{,-cryptographyMaster,-cryptographyMinimum},py27-twistedMaster,pypi-readme,check-manifest,flake8,docs,coverage-report
+envlist = {pypy,py26,py27,py34,py35,py36}{,-cryptographyMaster,-cryptographyMinimum},py27-twistedMaster,pypi-readme,check-manifest,flake8,docs,coverage-report
 
 [testenv]
 whitelist_externals =