Maidstone Borough within Kent
 
Maldon Borough within Essex
 
Malmesbury Borough within Wiltshire
 
Malton Borough within Yorkshire
 
Marlborough Borough within Wiltshire
 
Merioneth Welsh 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 Boroughs Linked borough within Montgomeryshire
 
Montgomeryshire Welsh County
 
Morpeth Borough within Northumberland
 
Much Wenlock Borough within Shropshire