diff --git a/.vpython3 b/.vpython3
index 95e52ee59e..d844b4dadd 100644
--- a/.vpython3
+++ b/.vpython3
@@ -44,3 +44,28 @@ wheel: <
   name: "infra/python/wheels/six-py2_py3"
   version: "version:1.15.0"
 >
+
+wheel: <
+  name: "infra/python/wheels/coverage/${vpython_platform}"
+  version: "version:5.5.chromium.2"
+>
+
+wheel: <
+ name: "infra/python/wheels/pbr-py2_py3"
+ version: "version:3.0.0"
+>
+
+wheel: <
+ name: "infra/python/wheels/funcsigs-py2_py3"
+ version: "version:1.0.2"
+>
+
+wheel: <
+  name: "infra/python/wheels/mock-py2_py3"
+  version: "version:2.0.0"
+>
+
+wheel: <
+  name: "infra/python/wheels/numpy/${vpython_platform}"
+  version: "version:1.20.3"
+>
\ No newline at end of file
diff --git a/tools/release/auto_roll.py b/tools/release/auto_roll.py
index 76247b1fb3..2aa4ff6829 100755
--- a/tools/release/auto_roll.py
+++ b/tools/release/auto_roll.py
@@ -80,7 +80,7 @@ class DetectRevisionToRoll(Step):
       version = self.GetVersionTag(revision)
       assert version, "Internal error. All recent releases should have a tag"
 
-      if SortingKey(self["last_version"]) < SortingKey(version):
+      if LooseVersion(self["last_version"]) < LooseVersion(version):
         self["roll"] = revision
         break
     else:
diff --git a/tools/release/common_includes.py b/tools/release/common_includes.py
index b61a3e2e27..0ccaa6aa11 100644
--- a/tools/release/common_includes.py
+++ b/tools/release/common_includes.py
@@ -31,7 +31,7 @@ from __future__ import print_function
 
 import argparse
 import datetime
-import httplib
+from distutils.version import LooseVersion
 import glob
 import imp
 import json
@@ -43,11 +43,20 @@ import sys
 import textwrap
 import time
 import urllib
-import urllib2
 
 from git_recipes import GitRecipesMixin
 from git_recipes import GitFailedException
 
+PYTHON3 = sys.version_info >= (3, 0)
+
+if PYTHON3:
+  import http.client as httplib
+  import urllib.request as urllib2
+else:
+  import httplib
+  import urllib2
+
+
 DAY_IN_SECONDS = 24 * 60 * 60
 PUSH_MSG_GIT_RE = re.compile(r".* \(based on (?P<git_rev>[a-fA-F0-9]+)\)$")
 PUSH_MSG_NEW_RE = re.compile(r"^Version \d+\.\d+\.\d+$")
@@ -92,16 +101,6 @@ def MSub(rexp, replacement, text):
   return re.sub(rexp, replacement, text, flags=re.MULTILINE)
 
 
-def SortingKey(version):
-  """Key for sorting version number strings: '3.11' > '3.2.1.1'"""
-  version_keys = map(int, version.split("."))
-  # Fill up to full version numbers to normalize comparison.
-  while len(version_keys) < 4:  # pragma: no cover
-    version_keys.append(0)
-  # Fill digits.
-  return ".".join(map("{0:04d}".format, version_keys))
-
-
 # Some commands don't like the pipe, e.g. calling vi from within the script or
 # from subscripts like git cl upload.
 def Command(cmd, args="", prefix="", pipe=True, cwd=None):
@@ -256,7 +255,7 @@ class GitInterface(VCInterface):
         lambda s: re.match(r"^branch\-heads/\d+\.\d+$", s),
         self.step.GitRemotes())
     # Remove 'branch-heads/' prefix.
-    return map(lambda s: s[13:], branches)
+    return [b[13:] for b in branches]
 
   def MainBranch(self):
     return "main"
@@ -557,7 +556,7 @@ class Step(GitRecipesMixin):
                          int(time_now - max_age)).strip()
 
     # Filter out revisions who's tag is off by one or more commits.
-    return filter(lambda r: self.GetVersionTag(r), revisions.splitlines())
+    return list(filter(self.GetVersionTag, revisions.splitlines()))
 
   def GetLatestVersion(self):
     # Use cached version if available.
@@ -571,7 +570,7 @@ class Step(GitRecipesMixin):
     only_version_tags = NormalizeVersionTags(all_tags)
 
     version = sorted(only_version_tags,
-                     key=SortingKey, reverse=True)[0]
+                     key=LooseVersion, reverse=True)[0]
     self["latest_version"] = version
     return version
 
diff --git a/tools/release/create_release.py b/tools/release/create_release.py
index d1a066f00b..62c5ed675f 100755
--- a/tools/release/create_release.py
+++ b/tools/release/create_release.py
@@ -10,10 +10,17 @@ import argparse
 import os
 import sys
 import tempfile
-import urllib2
 
 from common_includes import *
 
+PYTHON3 = sys.version_info >= (3, 0)
+
+if PYTHON3:
+  import urllib.request as urllib2
+else:
+  import urllib2
+
+
 class Preparation(Step):
   MESSAGE = "Preparation."
 
@@ -48,7 +55,7 @@ class IncrementVersion(Step):
     # Use the highest version from main or from tags to determine the new
     # version.
     authoritative_version = sorted(
-        [main_version, latest_version], key=SortingKey)[1]
+        [main_version, latest_version], key=LooseVersion)[1]
     self.StoreVersion(authoritative_version, "authoritative_")
 
     # Variables prefixed with 'new_' contain the new version numbers for the
diff --git a/tools/run_perf.py b/tools/run_perf.py
index 1e22b298a8..b394c3af03 100644
--- a/tools/run_perf.py
+++ b/tools/run_perf.py
@@ -289,7 +289,8 @@ def RunResultsProcessor(results_processor, output, count):
       stderr=subprocess.PIPE,
   )
   new_output = copy.copy(output)
-  new_output.stdout, _ = p.communicate(input=output.stdout)
+  new_output.stdout = p.communicate(
+      input=output.stdout.encode('utf-8'))[0].decode('utf-8')
   logging.info('>>> Processed stdout (#%d):\n%s', count, output.stdout)
   return new_output
 
diff --git a/tools/testrunner/local/command.py b/tools/testrunner/local/command.py
index df603d79d2..6942d1b9a4 100644
--- a/tools/testrunner/local/command.py
+++ b/tools/testrunner/local/command.py
@@ -19,6 +19,7 @@ from ..local.android import (
 from ..local import utils
 from ..objects import output
 
+PYTHON3 = sys.version_info >= (3, 0)
 
 BASE_DIR = os.path.normpath(
     os.path.join(os.path.dirname(os.path.abspath(__file__)), '..' , '..', '..'))
@@ -114,11 +115,17 @@ class BaseCommand(object):
 
       timer.cancel()
 
+    def convert(stream):
+      if PYTHON3:
+        return stream.decode('utf-8', 'replace')
+      else:
+        return stream.decode('utf-8', 'replace').encode('utf-8')
+
     return output.Output(
       process.returncode,
       timeout_occured[0],
-      stdout.decode('utf-8', 'replace').encode('utf-8'),
-      stderr.decode('utf-8', 'replace').encode('utf-8'),
+      convert(stdout),
+      convert(stderr),
       process.pid,
       duration
     )
diff --git a/tools/torque/format-torque.py b/tools/torque/format-torque.py
index 638ca100fb..98ae087ca1 100755
--- a/tools/torque/format-torque.py
+++ b/tools/torque/format-torque.py
@@ -15,6 +15,14 @@ import sys
 import re
 from subprocess import Popen, PIPE
 
+PYTHON3 = sys.version_info >= (3, 0)
+
+def maybe_decode(arg, encoding="utf-8"):
+  return arg.decode(encoding) if PYTHON3 else arg
+
+def maybe_encode(arg, encoding="utf-8"):
+  return arg.encode(encoding) if PYTHON3 else arg
+
 kPercentEscape = r'α';  # Unicode alpha
 kDerefEscape = r'☆'; # Unicode star
 kAddressofEscape = r'⌂'; # Unicode house
@@ -103,8 +111,8 @@ def process(filename, lint, should_format):
     p = Popen(['clang-format', '-assume-filename=.ts'], stdin=PIPE, stdout=PIPE, stderr=PIPE, shell=True)
   else:
     p = Popen(['clang-format', '-assume-filename=.ts'], stdin=PIPE, stdout=PIPE, stderr=PIPE)
-  output, err = p.communicate(preprocess(content))
-  output = postprocess(output)
+  output, err = p.communicate(maybe_encode(preprocess(content)))
+  output = postprocess(maybe_decode(output))
   rc = p.returncode
   if (rc != 0):
     print("error code " + str(rc) + " running clang-format. Exiting...")
diff --git a/tools/unittests/run_perf_test.py b/tools/unittests/run_perf_test.py
index 28f71b2b33..6d8c5e2a13 100755
--- a/tools/unittests/run_perf_test.py
+++ b/tools/unittests/run_perf_test.py
@@ -28,6 +28,8 @@ TEST_DATA = os.path.join(BASE_DIR, 'unittests', 'testdata')
 
 TEST_WORKSPACE = os.path.join(tempfile.gettempdir(), 'test-v8-run-perf')
 
+SORT_KEY = lambda x: x['graphs']
+
 V8_JSON = {
   'path': ['.'],
   'owners': ['username@chromium.org'],
@@ -196,8 +198,8 @@ class PerfTest(unittest.TestCase):
       {'units': units,
        'graphs': [suite, trace['name']],
        'results': trace['results'],
-       'stddev': trace['stddev']} for trace in traces]),
-      sorted(self._LoadResults(file_name)['traces']))
+       'stddev': trace['stddev']} for trace in traces], key=SORT_KEY),
+      sorted(self._LoadResults(file_name)['traces'], key=SORT_KEY))
 
   def _VerifyRunnableDurations(self, runs, timeout, file_name=None):
     self.assertListEqual([
@@ -368,7 +370,7 @@ class PerfTest(unittest.TestCase):
        'graphs': ['test', 'DeltaBlue'],
        'results': [200.0],
        'stddev': ''},
-      ]), sorted(self._LoadResults()['traces']))
+      ], key=SORT_KEY), sorted(self._LoadResults()['traces'], key=SORT_KEY))
     self._VerifyErrors([])
     self._VerifyMockMultiple(
         (os.path.join('out', 'x64.release', 'd7'), '--flag', 'run.js'),
@@ -605,7 +607,7 @@ class PerfTest(unittest.TestCase):
         'results': [2.1, 2.1],
         'stddev': '',
       },
-    ]), sorted(results['traces']))
+    ], key=SORT_KEY), sorted(results['traces'], key=SORT_KEY))
 
   def testResultsProcessor(self):
     results = self._RunPerf('d8_mocked2.py', 'test2.json')
diff --git a/tools/unittests/run_tests_test.py b/tools/unittests/run_tests_test.py
index 3581996ae4..762d3096ec 100755
--- a/tools/unittests/run_tests_test.py
+++ b/tools/unittests/run_tests_test.py
@@ -30,7 +30,11 @@ import sys
 import tempfile
 import unittest
 
-from cStringIO import StringIO
+# TODO(https://crbug.com/1292016): Remove after Python3 migration.
+try:
+  from cStringIO import StringIO
+except ImportError:
+  from io import StringIO
 
 TOOLS_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 TEST_DATA_ROOT = os.path.join(TOOLS_ROOT, 'unittests', 'testdata')
@@ -277,7 +281,9 @@ class SystemTest(unittest.TestCase):
     # We need lexicographic sorting here to avoid non-deterministic behaviour
     # The original sorting key is duration, but in our fake test we have
     # non-deterministic durations before we reset them to 1
-    json_output['slowest_tests'].sort(key= lambda x: str(x))
+    def sort_key(x):
+      return str(sorted(x.items()))
+    json_output['slowest_tests'].sort(key=sort_key)
 
     with open(os.path.join(TEST_DATA_ROOT, expected_results_name)) as f:
       expected_test_results = json.load(f)
diff --git a/tools/v8_presubmit.py b/tools/v8_presubmit.py
index 508326cebf..1d2d7b1c6e 100755
--- a/tools/v8_presubmit.py
+++ b/tools/v8_presubmit.py
@@ -41,20 +41,28 @@ except ImportError as e:
 
 
 import json
+import multiprocessing
 import optparse
 import os
 from os.path import abspath, join, dirname, basename, exists
 import pickle
 import re
-import sys
 import subprocess
-import multiprocessing
 from subprocess import PIPE
+import sys
 
 from testrunner.local import statusfile
 from testrunner.local import testsuite
 from testrunner.local import utils
 
+PYTHON3 = sys.version_info >= (3, 0)
+
+def maybe_decode(arg, encoding="utf-8"):
+  return arg.decode(encoding) if PYTHON3 else arg
+
+def maybe_encode(arg, encoding="utf-8"):
+  return arg.encode(encoding) if PYTHON3 else arg
+
 # Special LINT rules diverging from default and reason.
 # build/header_guard: Our guards have the form "V8_FOO_H_", not "SRC_FOO_H_".
 #   We now run our own header guard check in PRESUBMIT.py.
@@ -92,7 +100,7 @@ def CppLintWorker(command):
     out_lines = ""
     error_count = -1
     while True:
-      out_line = process.stderr.readline()
+      out_line = maybe_decode(process.stderr.readline())
       if out_line == '' and process.poll() != None:
         if error_count == -1:
           print("Failed to process %s" % command.pop())
@@ -118,7 +126,7 @@ def TorqueLintWorker(command):
     out_lines = ""
     error_count = 0
     while True:
-      out_line = process.stderr.readline()
+      out_line = maybe_decode(process.stderr.readline())
       if out_line == '' and process.poll() != None:
         break
       out_lines += out_line
@@ -148,7 +156,7 @@ def JSLintWorker(command):
         sys.stdout.write("error code " + str(rc) + " running clang-format.\n")
         return rc
 
-      if output != contents:
+      if maybe_decode(output) != contents:
         return 1
 
       return 0
@@ -206,7 +214,7 @@ class FileContentsCache(object):
     for file in files:
       try:
         handle = open(file, "r")
-        file_sum = md5er(handle.read()).digest()
+        file_sum = md5er(maybe_encode(handle.read())).digest()
         if not file in self.sums or self.sums[file] != file_sum:
           changed_or_new.append(file)
           self.sums[file] = file_sum
@@ -490,7 +498,7 @@ class SourceProcessor(SourceFileProcessor):
       output = subprocess.Popen('git ls-files --full-name',
                                 stdout=PIPE, cwd=path, shell=True)
       result = []
-      for file in output.stdout.read().split():
+      for file in maybe_decode(output.stdout.read()).split():
         for dir_part in os.path.dirname(file).replace(os.sep, '/').split('/'):
           if self.IgnoreDir(dir_part):
             break
@@ -623,8 +631,8 @@ class SourceProcessor(SourceFileProcessor):
     violations = 0
     for file in files:
       try:
-        handle = open(file)
-        contents = handle.read()
+        handle = open(file, "rb")
+        contents = maybe_decode(handle.read(), "ISO-8859-1")
         if len(contents) > 0 and not self.ProcessContents(file, contents):
           success = False
           violations += 1