diff --git a/Meta/lint-ci.sh b/Meta/lint-ci.sh
index 2467757df37..ec91e941fd8 100755
--- a/Meta/lint-ci.sh
+++ b/Meta/lint-ci.sh
@@ -20,6 +20,7 @@ for cmd in \
         Meta/check-style.sh \
         Meta/lint-executable-resources.sh \
         Meta/lint-ipc-ids.sh \
+        Meta/lint-keymaps.py \
         Meta/lint-shell-scripts.sh \
         Meta/lint-prettier.sh \
         Meta/lint-python.sh; do
diff --git a/Meta/lint-keymaps.py b/Meta/lint-keymaps.py
new file mode 100755
index 00000000000..27508804e45
--- /dev/null
+++ b/Meta/lint-keymaps.py
@@ -0,0 +1,128 @@
+#!/usr/bin/env python3
+
+import json
+import os
+import sys
+
+
+PERMITTED_MAPS = ['map', 'shift_map', 'alt_map', 'altgr_map', 'shift_altgr_map']
+REQUIRED_MAPS = ['map', 'shift_map', 'alt_map']
+# See Userland/Libraries/LibKeyboard/CharacterMapFile.cpp
+# and Userland/Libraries/LibKeyboard/CharacterMap.cpp.
+GOOD_MAP_LENGTHS = {90, 128}
+
+
+def report(filename, problem):
+    print('{}: {}'.format(filename, problem))
+
+
+def validate_single_map(filename, mapname, values):
+    all_good = True
+
+    if not isinstance(values, list):
+        report(filename, '"{}" is not an array'.format(mapname))
+        return False  # Cannot continue other checks
+
+    if not any(values):
+        report(filename, 'no values set in {}'.format(mapname))
+        all_good = False
+
+    for i, c in enumerate(values):
+        if len(c) > 1:
+            report(filename, 'more than one character ("{}") for charmap index {} of {}'.format(c, i, mapname))
+            all_good = False
+
+    # TODO: Require that a few keys are set?
+
+    if len(values) not in GOOD_MAP_LENGTHS:
+        report(filename, 'length {} of map {} is suspicious. Off-by-one?'.format(len(values), mapname))
+        all_good = False
+
+    return all_good
+
+
+def validate_fullmap(filename, fullmap):
+    all_good = True
+
+    if not isinstance(fullmap, dict):
+        report(filename, 'is not an object')
+        return False  # Cannot continue other checks
+
+    for name, map_ in fullmap.items():
+        if name not in PERMITTED_MAPS:
+            report(filename, 'contains unknown entry {}'.format(name))
+            all_good = False
+
+        all_good &= validate_single_map(filename, name, map_)
+
+    for name in REQUIRED_MAPS:
+        if name not in fullmap:
+            report(filename, 'map {} is missing'.format(name))
+            all_good = False
+
+    if 'altgr_map' in fullmap and 'alt_map' in fullmap and fullmap['altgr_map'] == fullmap['alt_map']:
+        report(filename, 'altgr_map is identical to alt_map. Remove altgr_map for the same effect.')
+        report(filename, '(Or add new characters!)')
+        all_good = False
+
+    if 'shift_altgr_map' in fullmap and 'alt_map' in fullmap and fullmap['shift_altgr_map'] == fullmap['alt_map']:
+        report(filename, 'shift_altgr_map is identical to alt_map. Remove shift_altgr_map for the same effect.')
+        report(filename, '(Or add new characters!)')
+        all_good = False
+
+    return all_good
+
+
+def run_with(filenames):
+    passed = 0
+    for filename in filenames:
+        with open(filename, 'r') as fp:
+            fullmap = json.load(fp)
+        if validate_fullmap(filename, fullmap):
+            passed += 1
+
+    print('{} out of {} keymaps passed.'.format(passed, len(filenames)))
+    return passed == len(filenames)
+
+
+def list_files_here():
+    filelist = []
+    for filename in os.listdir():
+        if filename.endswith('.json'):
+            filelist.append(filename)
+        else:
+            report(filename, 'weird filename (ignored)')
+    # Files are in "filesystem" order. Sort them for slightly more
+    # aesthetically pleasing output.
+    filelist.sort()
+    return filelist
+
+
+def run_here():
+    return run_with(list_files_here())
+
+
+def display_for(filename, index):
+    with open(filename, 'r') as fp:
+        fullmap = json.load(fp)
+    for name in PERMITTED_MAPS:
+        c = None
+        if name in fullmap:
+            m = fullmap[name]
+            if len(m) > index and m[index]:
+                c = m[index]
+        if c is None:
+            print('{}: None'.format(name))
+        else:
+            print('{}: "{}"'.format(name, c))
+
+
+if __name__ == '__main__':
+    os.chdir(os.path.dirname(__file__) + "/../Base/res/keymaps/")
+    if len(sys.argv) == 1:
+        exit(0 if run_here() else 1)
+    elif len(sys.argv) == 3:
+        display_for('{}.json'.format(sys.argv[1]), int(sys.argv[2], 0))
+    else:
+        print('USAGE: {} [mapcode index]'.format(sys.argv[0]), file=sys.stderr)
+        exit(1)