diff --git a/docs/source/conf.py b/docs/source/conf.py
index fd0d4b92..bf6d7ed1 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -1,7 +1,6 @@
 # -*- coding: utf-8 -*-
 #
 import os
-import shlex
 import sys
 
 # Set paths
diff --git a/examples/external-oauth/whoami-oauth-basic.py b/examples/external-oauth/whoami-oauth-basic.py
index ad98115c..2aca9f55 100644
--- a/examples/external-oauth/whoami-oauth-basic.py
+++ b/examples/external-oauth/whoami-oauth-basic.py
@@ -5,13 +5,11 @@ so all URLs and requests necessary for OAuth with JupyterHub should be in one pl
 """
 import json
 import os
-import sys
 from urllib.parse import urlencode
 from urllib.parse import urlparse
 
 from tornado import log
 from tornado import web
-from tornado.auth import OAuth2Mixin
 from tornado.httpclient import AsyncHTTPClient
 from tornado.httpclient import HTTPRequest
 from tornado.httputil import url_concat
diff --git a/examples/service-announcement/announcement.py b/examples/service-announcement/announcement.py
index 2b140fdb..a0cf5964 100644
--- a/examples/service-announcement/announcement.py
+++ b/examples/service-announcement/announcement.py
@@ -4,7 +4,6 @@ import json
 import os
 
 from tornado import escape
-from tornado import gen
 from tornado import ioloop
 from tornado import web
 
diff --git a/examples/service-whoami-flask/jupyterhub_config.py b/examples/service-whoami-flask/jupyterhub_config.py
index 54d3c736..63ddaa38 100644
--- a/examples/service-whoami-flask/jupyterhub_config.py
+++ b/examples/service-whoami-flask/jupyterhub_config.py
@@ -1,6 +1,3 @@
-import os
-import sys
-
 c.JupyterHub.services = [
     {
         'name': 'whoami',
diff --git a/examples/service-whoami/jupyterhub_config.py b/examples/service-whoami/jupyterhub_config.py
index d9ccd889..1d1f9435 100644
--- a/examples/service-whoami/jupyterhub_config.py
+++ b/examples/service-whoami/jupyterhub_config.py
@@ -1,4 +1,3 @@
-import os
 import sys
 
 c.JupyterHub.services = [
diff --git a/examples/service-whoami/whoami-oauth.py b/examples/service-whoami/whoami-oauth.py
index c1a576c9..72c97dda 100644
--- a/examples/service-whoami/whoami-oauth.py
+++ b/examples/service-whoami/whoami-oauth.py
@@ -6,7 +6,6 @@ showing the user their own info.
 """
 import json
 import os
-from getpass import getuser
 from urllib.parse import urlparse
 
 from tornado.httpserver import HTTPServer
@@ -25,6 +24,7 @@ class WhoAmIHandler(HubOAuthenticated, RequestHandler):
     # `getuser()` here would mean only the user who started the service
     # can access the service:
 
+    # from getpass import getuser
     # hub_users = {getuser()}
 
     @authenticated
diff --git a/examples/service-whoami/whoami.py b/examples/service-whoami/whoami.py
index 6dc56c9e..2a5a3373 100644
--- a/examples/service-whoami/whoami.py
+++ b/examples/service-whoami/whoami.py
@@ -4,7 +4,6 @@ This serves `/services/whoami/`, authenticated with the Hub, showing the user th
 """
 import json
 import os
-from getpass import getuser
 from urllib.parse import urlparse
 
 from tornado.httpserver import HTTPServer
@@ -21,6 +20,7 @@ class WhoAmIHandler(HubAuthenticated, RequestHandler):
     # `getuser()` here would mean only the user who started the service
     # can access the service:
 
+    # from getpass import getuser
     # hub_users = {getuser()}
 
     @authenticated
diff --git a/jupyterhub/apihandlers/groups.py b/jupyterhub/apihandlers/groups.py
index 78e833f7..e6b439ba 100644
--- a/jupyterhub/apihandlers/groups.py
+++ b/jupyterhub/apihandlers/groups.py
@@ -3,7 +3,6 @@
 # Distributed under the terms of the Modified BSD License.
 import json
 
-from tornado import gen
 from tornado import web
 
 from .. import orm
diff --git a/jupyterhub/apihandlers/proxy.py b/jupyterhub/apihandlers/proxy.py
index 83901832..0a43583b 100644
--- a/jupyterhub/apihandlers/proxy.py
+++ b/jupyterhub/apihandlers/proxy.py
@@ -2,12 +2,9 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 import json
-from urllib.parse import urlparse
 
-from tornado import gen
 from tornado import web
 
-from .. import orm
 from ..utils import admin_only
 from .base import APIHandler
 
diff --git a/jupyterhub/crypto.py b/jupyterhub/crypto.py
index 57bd00d3..039201b1 100644
--- a/jupyterhub/crypto.py
+++ b/jupyterhub/crypto.py
@@ -6,7 +6,6 @@ from concurrent.futures import ThreadPoolExecutor
 
 from traitlets import Any
 from traitlets import default
-from traitlets import Dict
 from traitlets import Integer
 from traitlets import List
 from traitlets import observe
diff --git a/jupyterhub/handlers/base.py b/jupyterhub/handlers/base.py
index 9606fa61..f8ecf348 100644
--- a/jupyterhub/handlers/base.py
+++ b/jupyterhub/handlers/base.py
@@ -2,7 +2,6 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 import asyncio
-import copy
 import json
 import math
 import random
@@ -27,14 +26,12 @@ from tornado.httputil import url_concat
 from tornado.ioloop import IOLoop
 from tornado.log import app_log
 from tornado.web import addslash
-from tornado.web import MissingArgumentError
 from tornado.web import RequestHandler
 
 from .. import __version__
 from .. import orm
 from ..metrics import PROXY_ADD_DURATION_SECONDS
 from ..metrics import PROXY_DELETE_DURATION_SECONDS
-from ..metrics import ProxyAddStatus
 from ..metrics import ProxyDeleteStatus
 from ..metrics import RUNNING_SERVERS
 from ..metrics import SERVER_POLL_DURATION_SECONDS
diff --git a/jupyterhub/handlers/metrics.py b/jupyterhub/handlers/metrics.py
index f7a95b62..0f63d9c3 100644
--- a/jupyterhub/handlers/metrics.py
+++ b/jupyterhub/handlers/metrics.py
@@ -1,7 +1,6 @@
 from prometheus_client import CONTENT_TYPE_LATEST
 from prometheus_client import generate_latest
 from prometheus_client import REGISTRY
-from tornado import gen
 
 from ..utils import metrics_authentication
 from .base import BaseHandler
diff --git a/jupyterhub/handlers/pages.py b/jupyterhub/handlers/pages.py
index 5cd1f4a7..ec378b9a 100644
--- a/jupyterhub/handlers/pages.py
+++ b/jupyterhub/handlers/pages.py
@@ -2,15 +2,12 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 import asyncio
-import codecs
-import copy
 import time
 from collections import defaultdict
 from datetime import datetime
 from http.client import responses
 
 from jinja2 import TemplateNotFound
-from tornado import gen
 from tornado import web
 from tornado.httputil import url_concat
 
@@ -464,7 +461,6 @@ class AdminHandler(BaseHandler):
 
         users = self.db.query(orm.User).outerjoin(orm.Spawner).order_by(*ordered)
         users = [self._user_from_orm(u) for u in users]
-        from itertools import chain
 
         running = []
         for u in users:
diff --git a/jupyterhub/oauth/provider.py b/jupyterhub/oauth/provider.py
index 6157223f..fd529cc9 100644
--- a/jupyterhub/oauth/provider.py
+++ b/jupyterhub/oauth/provider.py
@@ -3,15 +3,12 @@
 implements https://oauthlib.readthedocs.io/en/latest/oauth2/server.html
 """
 from datetime import datetime
-from urllib.parse import urlparse
 
 from oauthlib import uri_validate
 from oauthlib.oauth2 import RequestValidator
 from oauthlib.oauth2 import WebApplicationServer
 from oauthlib.oauth2.rfc6749.grant_types import authorization_code
 from oauthlib.oauth2.rfc6749.grant_types import base
-from sqlalchemy.orm import scoped_session
-from tornado import web
 from tornado.escape import url_escape
 from tornado.log import app_log
 
diff --git a/jupyterhub/proxy.py b/jupyterhub/proxy.py
index cbe1cba3..0666bcda 100644
--- a/jupyterhub/proxy.py
+++ b/jupyterhub/proxy.py
@@ -24,7 +24,6 @@ import time
 from functools import wraps
 from subprocess import Popen
 from urllib.parse import quote
-from urllib.parse import urlparse
 
 from tornado import gen
 from tornado.httpclient import AsyncHTTPClient
diff --git a/jupyterhub/spawner.py b/jupyterhub/spawner.py
index 4abc355b..56761516 100644
--- a/jupyterhub/spawner.py
+++ b/jupyterhub/spawner.py
@@ -4,8 +4,6 @@ Contains base Spawner class & default implementation
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 import ast
-import asyncio
-import errno
 import json
 import os
 import pipes
diff --git a/jupyterhub/tests/test_api.py b/jupyterhub/tests/test_api.py
index aedb4426..47751621 100644
--- a/jupyterhub/tests/test_api.py
+++ b/jupyterhub/tests/test_api.py
@@ -1,5 +1,4 @@
 """Tests for the REST API."""
-import asyncio
 import json
 import re
 import sys
diff --git a/jupyterhub/tests/test_app.py b/jupyterhub/tests/test_app.py
index bc59176b..bce50ae6 100644
--- a/jupyterhub/tests/test_app.py
+++ b/jupyterhub/tests/test_app.py
@@ -7,13 +7,11 @@ import time
 from subprocess import check_output
 from subprocess import PIPE
 from subprocess import Popen
-from subprocess import run
 from tempfile import NamedTemporaryFile
 from tempfile import TemporaryDirectory
 from unittest.mock import patch
 
 import pytest
-from tornado import gen
 from traitlets.config import Config
 
 from .. import orm
diff --git a/jupyterhub/tests/test_auth.py b/jupyterhub/tests/test_auth.py
index 10ae0b1a..a2fb98c5 100644
--- a/jupyterhub/tests/test_auth.py
+++ b/jupyterhub/tests/test_auth.py
@@ -1,7 +1,6 @@
 """Tests for PAM authentication"""
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-import os
 from unittest import mock
 
 import pytest
diff --git a/jupyterhub/tests/test_auth_expiry.py b/jupyterhub/tests/test_auth_expiry.py
index 781c751b..48f85eb4 100644
--- a/jupyterhub/tests/test_auth_expiry.py
+++ b/jupyterhub/tests/test_auth_expiry.py
@@ -7,7 +7,6 @@ authentication can expire in a number of ways:
 - doesn't need refresh
 - needs refresh and cannot be refreshed without new login
 """
-import asyncio
 from contextlib import contextmanager
 from unittest import mock
 from urllib.parse import parse_qs
diff --git a/jupyterhub/tests/test_dummyauth.py b/jupyterhub/tests/test_dummyauth.py
index 3f34c343..dbeaf583 100644
--- a/jupyterhub/tests/test_dummyauth.py
+++ b/jupyterhub/tests/test_dummyauth.py
@@ -1,8 +1,6 @@
 """Tests for dummy authentication"""
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-import pytest
-
 from jupyterhub.auth import DummyAuthenticator
 
 
diff --git a/jupyterhub/tests/test_internal_ssl_app.py b/jupyterhub/tests/test_internal_ssl_app.py
index 95b382c4..cae0519b 100644
--- a/jupyterhub/tests/test_internal_ssl_app.py
+++ b/jupyterhub/tests/test_internal_ssl_app.py
@@ -1,8 +1,6 @@
 """Test the JupyterHub entry point with internal ssl"""
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-import sys
-
 import jupyterhub.tests.mocking
 from jupyterhub.tests.test_app import *
 
diff --git a/jupyterhub/tests/test_proxy.py b/jupyterhub/tests/test_proxy.py
index 0de5748b..e912bc62 100644
--- a/jupyterhub/tests/test_proxy.py
+++ b/jupyterhub/tests/test_proxy.py
@@ -2,7 +2,6 @@
 import json
 import os
 from contextlib import contextmanager
-from queue import Queue
 from subprocess import Popen
 from urllib.parse import quote
 from urllib.parse import urlparse
diff --git a/jupyterhub/tests/test_services.py b/jupyterhub/tests/test_services.py
index 248de1b1..127a9f45 100644
--- a/jupyterhub/tests/test_services.py
+++ b/jupyterhub/tests/test_services.py
@@ -2,18 +2,13 @@
 import asyncio
 import os
 import sys
-import time
 from binascii import hexlify
 from contextlib import contextmanager
 from subprocess import Popen
-from threading import Event
 
-import pytest
-import requests
 from async_generator import async_generator
 from async_generator import asynccontextmanager
 from async_generator import yield_
-from tornado import gen
 from tornado.ioloop import IOLoop
 
 from ..utils import maybe_future
diff --git a/jupyterhub/tests/test_services_auth.py b/jupyterhub/tests/test_services_auth.py
index de4d73e9..a57ba871 100644
--- a/jupyterhub/tests/test_services_auth.py
+++ b/jupyterhub/tests/test_services_auth.py
@@ -11,7 +11,6 @@ from threading import Thread
 from unittest import mock
 from urllib.parse import urlparse
 
-import pytest
 import requests
 import requests_mock
 from pytest import raises
diff --git a/jupyterhub/tests/test_singleuser.py b/jupyterhub/tests/test_singleuser.py
index 1bd08696..0e4d3bd7 100644
--- a/jupyterhub/tests/test_singleuser.py
+++ b/jupyterhub/tests/test_singleuser.py
@@ -3,8 +3,6 @@ import sys
 from subprocess import check_output
 from urllib.parse import urlparse
 
-import pytest
-
 import jupyterhub
 from ..utils import url_path_join
 from .mocking import public_url
diff --git a/jupyterhub/utils.py b/jupyterhub/utils.py
index 851b4d53..524fd093 100644
--- a/jupyterhub/utils.py
+++ b/jupyterhub/utils.py
@@ -444,7 +444,6 @@ def print_stacks(file=sys.stderr):
     # local imports because these will not be used often,
     # no need to add them to startup
     import asyncio
-    import resource
     import traceback
     from .log import coroutine_frames
 
diff --git a/setup.py b/setup.py
index 5a5f4176..dbd1f3d3 100755
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,6 @@ from __future__ import print_function
 import os
 import shutil
 import sys
-from glob import glob
 from subprocess import check_call
 
 from setuptools import setup