| Australia |
Mastiff Club Of Victoria Inc. |
| |
| Austria |
Molosser Club Austria |
| |
| Belgium |
Mastiff Club Belgium |
| |
| Canada |
Canadian Mastiff Club |
| |
Mastiff Fanciers of Western Canada |
| |
| Czech Republic |
Moloss Club CZ |
| |
| Denmark |
Dansk Mastiff Klub |
| |
| France |
Club français du Bullmastiff et du Mastiff |
| |
| Germany |
Old English Mastiff Club Deutschland e.V. |
| |
| Norway |
Norwegian English Mastiff Club |
| |
| Spain |
Club Espanol de los Molosos de Arena |
| |
| Sweden |
Svenska Mastiffklubben |
| |
| United Kingdom |
Old English Mastiff Club |
|
Mastiff Association |
| |
| United States |
Garden State Mastiff Fanciers |
|
Mastiff Club of America |
| |
Mid-west Mastiff Fanciers |
|
Pacific Northwest Mastiff Fanciers |
| |
Pacific Southwest Mastiff Club |
|
Lone Star Mastiff Fanciers |
| |
Redwood Empire Mastiff Club |
