diff --git a/.flake8 b/.flake8
new file mode 100644
index 00000000000..331c6700a53
--- /dev/null
+++ b/.flake8
@@ -0,0 +1,4 @@
+[flake8]
+max-line-length = 79
+select = B,C,E,F,W,T4,B9,B950
+ignore = E402, W503, W504
diff --git a/.github/workflows/test_fast.yml b/.github/workflows/test_fast.yml
index 53cb6348c0a..377a23997ad 100644
--- a/.github/workflows/test_fast.yml
+++ b/.github/workflows/test_fast.yml
@@ -29,7 +29,6 @@ jobs:
 
       - name: Style
         run: |
-          pycodestyle
           flake8
           etc/bin/shellchecker
 
diff --git a/.isort.cfg b/.isort.cfg
new file mode 100644
index 00000000000..a8ee33b7a5d
--- /dev/null
+++ b/.isort.cfg
@@ -0,0 +1,7 @@
+[settings]
+multi_line_output=3
+include_trailing_comma=true
+force_grid_wrap=0
+use_parentheses=true
+ensure_newline_before_comments=true
+line_length=79
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 00000000000..283ce36b433
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,33 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+  - repo: https://github.com/timothycrosley/isort
+    rev: 5.6.4
+    hooks:
+      - id: isort
+        files: .*.py
+  - repo: https://github.com/psf/black
+    rev: 20.8b1
+    hooks:
+      - id: black
+        args: ["--line-length", "79", "-t", "py37"]
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.2.0
+    hooks:
+      - id: check-ast
+      - id: check-case-conflict
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: debug-statements
+      - id: check-added-large-files
+      - id: check-docstring-first
+      - id: check-yaml
+        exclude: conda/meta.yaml
+  - repo: https://github.com/PyCQA/flake8
+    rev: 3.8.4
+    hooks:
+      - id: flake8
+  - repo: https://github.com/PyCQA/bandit
+    rev: 1.6.2
+    hooks:
+      - id: bandit
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index e57c995428a..be93c06257f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -24,6 +24,13 @@ add their details to the [Code Contributors](#code-contributors) section of
 this file as part of their first Pull Request, and reviewers are responsible
 for checking this before merging the new branch into *master*.
 
+To start modifying cylc-flow and test your changes, first call
+`pip install -e .[all]` to install the package in development mode along with
+all dependencies.  Then call `pre-commit install` so that the git pre-commit
+hooks will run on commit. [pre-commit ](https://pre-commit.com) is used for
+code style consistency. It can also be run manually with the `pre-commit run`
+command (use --files to run on a reduced set of files).
+
 ## Code Contributors
 
 The following people have contributed to this code under the terms of
diff --git a/setup.py b/setup.py
index 9ffeb8841f4..638150f05fd 100644
--- a/setup.py
+++ b/setup.py
@@ -88,6 +88,9 @@ def find_version(*file_paths):
     'main_loop-log_memory': [
         'pympler',
         'matplotlib'
+    ],
+    "dev": [
+        "pre-commit"
     ]
 }
 extra_requires['all'] = (
diff --git a/tests/functional/jinja2/filters/Jinja2Filters/truly.py b/tests/functional/jinja2/filters/Jinja2Filters/truly.py
index bc71ec7f1ba..6b0359ec9d5 100644
--- a/tests/functional/jinja2/filters/Jinja2Filters/truly.py
+++ b/tests/functional/jinja2/filters/Jinja2Filters/truly.py
@@ -14,5 +14,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+
 def truly(bar):
     return 'true'
diff --git a/tests/functional/validate/68-trailing_whitespace.t b/tests/functional/validate/68-trailing_whitespace.t
index 32e1201cab9..3ef9bf46d50 100644
--- a/tests/functional/validate/68-trailing_whitespace.t
+++ b/tests/functional/validate/68-trailing_whitespace.t
@@ -27,8 +27,8 @@ cat >'flow.cylc' <<'__FLOW_CONFIG__'
     final cycle point = 20010101T18
     [[graph]]
         T00 = """
-            # NOTE: don't let editor strip trailing space on next line
-            foo | bar \ 
+            # pre-commit hook removes trailing space so add it with sed below
+            foo | bar BACKSLASH_TRAILING_WHITESPACE
             => baz & qux
             pub
         """
@@ -38,6 +38,8 @@ cat >'flow.cylc' <<'__FLOW_CONFIG__'
         """
 __FLOW_CONFIG__
 
+sed -i 's/BACKSLASH_TRAILING_WHITESPACE/\\ /' 'flow.cylc'
+
 run_fail "${TEST_NAME_BASE}-simple-fail" cylc validate 'flow.cylc'
 cmp_ok "${TEST_NAME_BASE}-simple-fail.stderr" <<'__ERR__'
 FileParseError: Syntax error line 7: Whitespace after the line continuation character (\).
diff --git a/tox.ini b/tox.ini
index 4172f0e826b..5836d9f6cbe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,10 +1,9 @@
 [pycodestyle]
+; E402 module level import not at top of file
+; W503/4 line break before/after binary operator
 ignore=
-    ; module level import not at top of file
     E402,
-    ; line break before binary operator
     W503,
-    ; line break after binary operator
     W504
 exclude=
     .git,