Maidstone Borough within Kent
 
Maldon Borough within Essex
 
Mallow Borough within Co. Cork
 
Malmesbury Borough within Wiltshire
 
Malton Borough within Yorkshire
 
Marlborough Borough within Wiltshire
 
Marylebone Borough within London
 
Merioneth County
 
Middlesex County
 
Midhurst Borough within Sussex
 
Milborne Port Borough within Somerset
 
Minehead Borough within Somerset
 
Mitchell Borough within Cornwall
 
Monmouth Borough within Monmouthshire
 
Monmouthshire County
 
Montgomery within Montgomeryshire
 
Montgomery Boroughs Borough within Montgomeryshire
 
Montgomeryshire County
 
Montrose Burghs County
 
Morpeth Borough within Northumberland