diff --git a/lib/python/qmk/cli/chibios/confmigrate.py b/lib/python/qmk/cli/chibios/confmigrate.py
index be1f2cd74468..ccf9afdfa109 100644
--- a/lib/python/qmk/cli/chibios/confmigrate.py
+++ b/lib/python/qmk/cli/chibios/confmigrate.py
@@ -3,13 +3,23 @@
 import re
 import sys
 import os
+from typing import TextIO, TypedDict
 
 from qmk.constants import QMK_FIRMWARE
 from qmk.path import normpath
-from milc import cli
+from milc import MILC, cli
 
 
-def eprint(*args, **kwargs):
+class Defines(TypedDict):
+    keys: list[str]
+    dict: dict[str, str]
+
+
+Override = tuple[str, str]
+Diff = tuple[list[Override], list[str], list[str]]
+
+
+def eprint(*args: object, **kwargs: object) -> None:
     print(*args, file=sys.stderr, **kwargs)
 
 
@@ -39,25 +49,27 @@ def eprint(*args, **kwargs):
 """
 
 
-def collect_defines(filepath):
+def collect_defines(filepath: str) -> Defines:
     with open(filepath, 'r', encoding='utf-8') as f:
         content = f.read()
         define_search = re.compile(r'(?m)^#\s*define\s+(?:.*\\\r?\n)*.*$', re.MULTILINE)
         value_search = re.compile(r'^#\s*define\s+(?P<name>[a-zA-Z0-9_]+(\([^\)]*\))?)\s*(?P<value>.*)', re.DOTALL)
         define_matches = define_search.findall(content)
 
-        defines = {"keys": [], "dict": {}}
+        defines: Defines = {"keys": [], "dict": {}}
         for define_match in define_matches:
             value_match = value_search.search(define_match)
+            if value_match is None:
+                raise RuntimeError
             defines["keys"].append(value_match.group("name"))
             defines["dict"][value_match.group("name")] = value_match.group("value")
         return defines
 
 
-def check_diffs(input_defs, reference_defs):
-    not_present_in_input = []
-    not_present_in_reference = []
-    to_override = []
+def check_diffs(input_defs: Defines, reference_defs: Defines) -> Diff:
+    not_present_in_input: list[str] = []
+    not_present_in_reference: list[str] = []
+    to_override: list[Override] = []
 
     for key in reference_defs["keys"]:
         if key not in input_defs["dict"]:
@@ -76,7 +88,7 @@ def check_diffs(input_defs, reference_defs):
     return (to_override, not_present_in_input, not_present_in_reference)
 
 
-def migrate_chconf_h(to_override, outfile):
+def migrate_chconf_h(to_override: list[Override], outfile: TextIO) -> None:
     print(file_header.format(cli.args.input.relative_to(QMK_FIRMWARE), cli.args.reference.relative_to(QMK_FIRMWARE)), file=outfile)
 
     for override in to_override:
@@ -86,7 +98,7 @@ def migrate_chconf_h(to_override, outfile):
     print("#include_next <chconf.h>\n", file=outfile)
 
 
-def migrate_halconf_h(to_override, outfile):
+def migrate_halconf_h(to_override: list[Override], outfile: TextIO) -> None:
     print(file_header.format(cli.args.input.relative_to(QMK_FIRMWARE), cli.args.reference.relative_to(QMK_FIRMWARE)), file=outfile)
 
     for override in to_override:
@@ -96,7 +108,7 @@ def migrate_halconf_h(to_override, outfile):
     print("#include_next <halconf.h>\n", file=outfile)
 
 
-def migrate_mcuconf_h(to_override, outfile):
+def migrate_mcuconf_h(to_override: list[Override], outfile: TextIO) -> None:
     print(file_header.format(cli.args.input.relative_to(QMK_FIRMWARE), cli.args.reference.relative_to(QMK_FIRMWARE)), file=outfile)
 
     print("#include_next <mcuconf.h>\n", file=outfile)
@@ -113,7 +125,7 @@ def migrate_mcuconf_h(to_override, outfile):
 @cli.argument('-d', '--delete', arg_only=True, action='store_true', help='If the file has no overrides, migration will delete the input file.')
 @cli.argument('-f', '--force', arg_only=True, action='store_true', help='Re-migrates an already migrated file, even if it doesn\'t detect a full ChibiOS config.')
 @cli.subcommand('Generates a migrated ChibiOS configuration file, as a result of comparing the input against a reference')
-def chibios_confmigrate(cli):
+def chibios_confmigrate(cli: MILC) -> None:
     """Generates a usable ChibiOS replacement configuration file, based on a fully-defined conf and a reference config.
     """
 
diff --git a/lib/python/qmk/cli/ci/validate_aliases.py b/lib/python/qmk/cli/ci/validate_aliases.py
index 7f781d43970b..49379f479de7 100644
--- a/lib/python/qmk/cli/ci/validate_aliases.py
+++ b/lib/python/qmk/cli/ci/validate_aliases.py
@@ -1,18 +1,19 @@
 """Validates the list of keyboard aliases.
 """
-from milc import cli
+from typing import Optional
+from milc import MILC, cli
 
 from qmk.keyboard import resolve_keyboard, keyboard_folder, keyboard_alias_definitions
 
 
-def _safe_keyboard_folder(target):
+def _safe_keyboard_folder(target: str) -> Optional[str]:
     try:
         return keyboard_folder(target)  # throws ValueError if it's invalid
     except Exception:
         return None
 
 
-def _target_keyboard_exists(target):
+def _target_keyboard_exists(target: Optional[str]) -> bool:
     # If there's no target, then we can't build it.
     if not target:
         return False
@@ -30,12 +31,12 @@ def _target_keyboard_exists(target):
 
 
 @cli.subcommand('Validates the list of keyboard aliases.', hidden=True)
-def ci_validate_aliases(cli):
+def ci_validate_aliases(cli: MILC) -> bool:
     aliases = keyboard_alias_definitions()
 
     success = True
     for alias in aliases.keys():
-        target = aliases[alias].get('target', None)
+        target: Optional[str] = aliases[alias].get('target', None)
         if not _target_keyboard_exists(target):
             cli.log.error(f'Keyboard alias {alias} has a target that doesn\'t exist: {target}')
             success = False
diff --git a/lib/python/qmk/cli/doctor/check.py b/lib/python/qmk/cli/doctor/check.py
index 2804a1d7df16..dbdad4fa059d 100644
--- a/lib/python/qmk/cli/doctor/check.py
+++ b/lib/python/qmk/cli/doctor/check.py
@@ -6,11 +6,18 @@
 from subprocess import DEVNULL, TimeoutExpired
 from tempfile import TemporaryDirectory
 from pathlib import Path
+from typing import TypedDict
 
 from milc import cli
 from qmk import submodules
 
 
+class Version(TypedDict):
+    major: int
+    minor: int
+    patch: int
+
+
 class CheckStatus(Enum):
     OK = 1
     WARNING = 2
@@ -30,8 +37,10 @@ class CheckStatus(Enum):
 }
 
 
-def _parse_gcc_version(version):
+def _parse_gcc_version(version: str) -> Version:
     m = re.match(r"(\d+)(?:\.(\d+))?(?:\.(\d+))?", version)
+    if m is None:
+        raise RuntimeError
 
     return {
         'major': int(m.group(1)),
@@ -40,7 +49,7 @@ def _parse_gcc_version(version):
     }
 
 
-def _check_arm_gcc_version():
+def _check_arm_gcc_version() -> CheckStatus:
     """Returns True if the arm-none-eabi-gcc version is not known to cause problems.
     """
     version_number = ESSENTIAL_BINARIES['arm-none-eabi-gcc']['output'].strip()
@@ -50,7 +59,7 @@ def _check_arm_gcc_version():
     return _check_arm_gcc_installation()
 
 
-def _check_arm_gcc_installation():
+def _check_arm_gcc_installation() -> CheckStatus:
     """Returns OK if the arm-none-eabi-gcc is fully installed and can produce binaries.
     """
     with TemporaryDirectory() as temp_dir:
@@ -77,7 +86,7 @@ def _check_arm_gcc_installation():
         return CheckStatus.OK
 
 
-def _check_avr_gcc_version():
+def _check_avr_gcc_version() -> CheckStatus:
     """Returns True if the avr-gcc version is not known to cause problems.
     """
     version_number = ESSENTIAL_BINARIES['avr-gcc']['output'].strip()
@@ -87,7 +96,7 @@ def _check_avr_gcc_version():
     return _check_avr_gcc_installation()
 
 
-def _check_avr_gcc_installation():
+def _check_avr_gcc_installation() -> CheckStatus:
     """Returns OK if the avr-gcc is fully installed and can produce binaries.
     """
     with TemporaryDirectory() as temp_dir:
@@ -114,7 +123,7 @@ def _check_avr_gcc_installation():
         return CheckStatus.OK
 
 
-def _check_avrdude_version():
+def _check_avrdude_version() -> CheckStatus:
     last_line = ESSENTIAL_BINARIES['avrdude']['output'].split('\n')[-2]
     version_number = last_line.split()[2][:-1]
     cli.log.info('Found avrdude version %s', version_number)
@@ -122,7 +131,7 @@ def _check_avrdude_version():
     return CheckStatus.OK
 
 
-def _check_dfu_util_version():
+def _check_dfu_util_version() -> CheckStatus:
     first_line = ESSENTIAL_BINARIES['dfu-util']['output'].split('\n')[0]
     version_number = first_line.split()[1]
     cli.log.info('Found dfu-util version %s', version_number)
@@ -130,7 +139,7 @@ def _check_dfu_util_version():
     return CheckStatus.OK
 
 
-def _check_dfu_programmer_version():
+def _check_dfu_programmer_version() -> CheckStatus:
     first_line = ESSENTIAL_BINARIES['dfu-programmer']['output'].split('\n')[0]
     version_number = first_line.split()[1]
     cli.log.info('Found dfu-programmer version %s', version_number)
@@ -138,7 +147,7 @@ def _check_dfu_programmer_version():
     return CheckStatus.OK
 
 
-def check_binaries():
+def check_binaries() -> CheckStatus:
     """Iterates through ESSENTIAL_BINARIES and tests them.
     """
     ok = CheckStatus.OK
@@ -155,7 +164,7 @@ def check_binaries():
     return ok
 
 
-def check_binary_versions():
+def check_binary_versions() -> list[CheckStatus]:
     """Check the versions of ESSENTIAL_BINARIES
     """
     checks = {
@@ -178,7 +187,7 @@ def check_binary_versions():
     return versions
 
 
-def check_submodules():
+def check_submodules() -> CheckStatus:
     """Iterates through all submodules to make sure they're cloned and up to date.
     """
     for submodule in submodules.status().values():
@@ -190,7 +199,7 @@ def check_submodules():
     return CheckStatus.OK
 
 
-def is_executable(command):
+def is_executable(command: str) -> bool:
     """Returns True if command exists and can be executed.
     """
     # Make sure the command is in the path.
@@ -213,7 +222,7 @@ def is_executable(command):
     return False
 
 
-def release_info(file='/etc/os-release'):
+def release_info(file: str = '/etc/os-release') -> dict[str, str]:
     """Parse release info to dict
     """
     ret = {}
diff --git a/lib/python/qmk/cli/doctor/linux.py b/lib/python/qmk/cli/doctor/linux.py
index f0850d4e6488..36cba6c275fa 100644
--- a/lib/python/qmk/cli/doctor/linux.py
+++ b/lib/python/qmk/cli/doctor/linux.py
@@ -3,6 +3,7 @@
 import platform
 import shutil
 from pathlib import Path
+from typing import Optional
 
 from milc import cli
 
@@ -10,11 +11,11 @@
 from .check import CheckStatus, release_info
 
 
-def _is_wsl():
+def _is_wsl() -> bool:
     return 'microsoft' in platform.uname().release.lower()
 
 
-def _udev_rule(vid, pid=None, *args):
+def _udev_rule(vid: str, pid: Optional[str] = None, *args: str) -> str:
     """ Helper function that return udev rules
     """
     rule = ""
@@ -30,8 +31,8 @@ def _udev_rule(vid, pid=None, *args):
     return rule
 
 
-def _generate_desired_rules(bootloader_vids_pids):
-    rules = dict()
+def _generate_desired_rules(bootloader_vids_pids: dict[str, set[tuple[str, str]]]) -> dict[str, set[str]]:
+    rules: dict[str, set[str]] = {}
     for bl in bootloader_vids_pids.keys():
         rules[bl] = set()
         for vid_pid in bootloader_vids_pids[bl]:
@@ -42,7 +43,7 @@ def _generate_desired_rules(bootloader_vids_pids):
     return rules
 
 
-def _deprecated_udev_rule(vid, pid=None):
+def _deprecated_udev_rule(vid: str, pid: Optional[str] = None) -> str:
     """ Helper function that return udev rules
 
     Note: these are no longer the recommended rules, this is just used to check for them
@@ -53,7 +54,7 @@ def _deprecated_udev_rule(vid, pid=None):
         return 'SUBSYSTEMS=="usb", ATTRS{idVendor}=="%s", MODE:="0666"' % vid
 
 
-def check_udev_rules():
+def check_udev_rules() -> CheckStatus:
     """Make sure the udev rules look good.
     """
     rc = CheckStatus.OK
@@ -111,13 +112,13 @@ def check_udev_rules():
     return rc
 
 
-def check_systemd():
+def check_systemd() -> bool:
     """Check if it's a systemd system
     """
     return bool(shutil.which("systemctl"))
 
 
-def check_modem_manager():
+def check_modem_manager() -> bool:
     """Returns True if ModemManager is running.
 
     """
@@ -131,7 +132,7 @@ def check_modem_manager():
     return False
 
 
-def os_test_linux():
+def os_test_linux() -> CheckStatus:
     """Run the Linux specific tests.
     """
     info = release_info()
diff --git a/lib/python/qmk/cli/doctor/macos.py b/lib/python/qmk/cli/doctor/macos.py
index 5d088c9492c6..4d9670bf6903 100644
--- a/lib/python/qmk/cli/doctor/macos.py
+++ b/lib/python/qmk/cli/doctor/macos.py
@@ -5,7 +5,7 @@
 from .check import CheckStatus
 
 
-def os_test_macos():
+def os_test_macos() -> CheckStatus:
     """Run the Mac specific tests.
     """
     cli.log.info("Detected {fg_cyan}macOS %s (%s){fg_reset}.", platform.mac_ver()[0], 'Apple Silicon' if platform.processor() == 'arm' else 'Intel')
diff --git a/lib/python/qmk/cli/doctor/main.py b/lib/python/qmk/cli/doctor/main.py
index 391353ebbfb1..1a81b8b4162c 100755
--- a/lib/python/qmk/cli/doctor/main.py
+++ b/lib/python/qmk/cli/doctor/main.py
@@ -5,7 +5,7 @@
 import platform
 from subprocess import DEVNULL
 
-from milc import cli
+from milc import MILC, cli
 from milc.questions import yesno
 
 from qmk import submodules
@@ -16,7 +16,7 @@
 from qmk.userspace import qmk_userspace_paths, qmk_userspace_validate, UserspaceValidationError
 
 
-def os_tests():
+def os_tests() -> CheckStatus:
     """Determine our OS and run platform specific tests
     """
     platform_id = platform.platform().lower()
@@ -35,7 +35,7 @@ def os_tests():
         return CheckStatus.WARNING
 
 
-def git_tests():
+def git_tests() -> CheckStatus:
     """Run Git-related checks
     """
     status = CheckStatus.OK
@@ -75,7 +75,7 @@ def git_tests():
     return status
 
 
-def output_submodule_status():
+def output_submodule_status() -> None:
     """Prints out information related to the submodule status.
     """
     cli.log.info('Submodule status:')
@@ -93,7 +93,7 @@ def output_submodule_status():
                 cli.log.error(f'- {sub_name}: <<< missing or unknown >>>')
 
 
-def userspace_tests(qmk_firmware):
+def userspace_tests(qmk_firmware) -> None:
     if qmk_firmware:
         cli.log.info(f'QMK home: {{fg_cyan}}{qmk_firmware}')
 
@@ -115,7 +115,7 @@ def userspace_tests(qmk_firmware):
 @cli.argument('-y', '--yes', action='store_true', arg_only=True, help='Answer yes to all questions.')
 @cli.argument('-n', '--no', action='store_true', arg_only=True, help='Answer no to all questions.')
 @cli.subcommand('Basic QMK environment checks')
-def doctor(cli):
+def doctor(cli: MILC) -> int:
     """Basic QMK environment checks.
 
     This is currently very simple, it just checks that all the expected binaries are on your system.
diff --git a/lib/python/qmk/cli/doctor/windows.py b/lib/python/qmk/cli/doctor/windows.py
index 26bb65374b84..00aae38e28f5 100644
--- a/lib/python/qmk/cli/doctor/windows.py
+++ b/lib/python/qmk/cli/doctor/windows.py
@@ -5,7 +5,7 @@
 from .check import CheckStatus, release_info
 
 
-def os_test_windows():
+def os_test_windows() -> CheckStatus:
     """Run the Windows specific tests.
     """
     win32_ver = platform.win32_ver()
diff --git a/lib/python/qmk/makefile.py b/lib/python/qmk/makefile.py
index ae95abbf2368..b1dc1a4c79f9 100644
--- a/lib/python/qmk/makefile.py
+++ b/lib/python/qmk/makefile.py
@@ -1,9 +1,10 @@
 """ Functions for working with Makefiles
 """
 from pathlib import Path
+from typing import Optional, Union
 
 
-def parse_rules_mk_file(file, rules_mk=None):
+def parse_rules_mk_file(filepath: Union[str, Path], rules_mk: Optional[dict[str, str]] = None) -> dict[str, str]:
     """Turn a rules.mk file into a dictionary.
 
     Args:
@@ -16,7 +17,7 @@ def parse_rules_mk_file(file, rules_mk=None):
     if not rules_mk:
         rules_mk = {}
 
-    file = Path(file)
+    file = Path(filepath)
     if file.exists():
         rules_mk_lines = file.read_text(encoding='utf-8').split("\n")
 
diff --git a/lib/python/qmk/util.py b/lib/python/qmk/util.py
index 8f99410e1de8..163b3dc4e83e 100644
--- a/lib/python/qmk/util.py
+++ b/lib/python/qmk/util.py
@@ -3,15 +3,16 @@
 import contextlib
 import multiprocessing
 import sys
+from typing import Union
 
 from milc import cli
 
-maybe_exit_should_exit = True
-maybe_exit_reraise = False
+maybe_exit_should_exit: bool = True
+maybe_exit_reraise: bool = False
 
 
 # Controls whether or not early `exit()` calls should be made
-def maybe_exit(rc):
+def maybe_exit(rc: Union[None, int, str]) -> None:
     if maybe_exit_should_exit:
         sys.exit(rc)
     if maybe_exit_reraise:
@@ -20,14 +21,14 @@ def maybe_exit(rc):
             raise e
 
 
-def maybe_exit_config(should_exit: bool = True, should_reraise: bool = False):
+def maybe_exit_config(should_exit: bool = True, should_reraise: bool = False) -> None:
     global maybe_exit_should_exit
     global maybe_exit_reraise
     maybe_exit_should_exit = should_exit
     maybe_exit_reraise = should_reraise
 
 
-def truthy(value, value_if_unknown=False):
+def truthy(value: object, value_if_unknown: bool = False) -> bool:
     """Returns True if the value is truthy, False otherwise.
 
     Deals with:
@@ -35,7 +36,7 @@ def truthy(value, value_if_unknown=False):
         False: 0, false, f, no, n, off
     """
     if value in {False, True}:
-        return bool(value)
+        return value is True
 
     test_value = str(value).strip().lower()