| Magnum Club Italy | Italy | | | | |
| Main Pain | GER | Frankfurt | 1992 | | |
| Mainely Bears | Maine | | | | |
| Mall City Cruisers | MI | Kalamazoo | | | |
| Manchester Super Chain | ENG | Manchester | 1983 | | |
| Manitoba Bears | CAN | Manitoba | | | |
| Mannheim Bears | Germany | | | | |
| Mansfield Bucks | VT | Burlington | | | |
| MasT | Ga | Atlanta | | | |
| MasT | MA | Boston | | | |
| MasT | New Jersey | | 2001 | | |
| MasT | IL | Chicago | 1988 | | |
| MasT | OH | Cincinatti | | | |
| MasT (Gay Male) | DC | Washington | 1999 | | |
| MasT (Pansexual) | DC | Washington | | | |
| MasT Greater LA | CA | Los Angeles | | | |
| MasT | Hampton Roads | | | | |
| MasT | TX | Houston | | | |
| Mast | FL | Jacksonville | 2003 | | |
| MasT | MO | Kansas City | 2003 | | |
| MasT | CA | Los Angeles | | | |
| MasT | NV | Las Vegas | | | |
| MasT | MN | Minneapolis | | | |
| MasT | Oklahoma | | | | |
| MasT | LA | New Orleans | | | |
| MasT | PA | Philadelphia | | | |
| MasT | AZ | Phoenix | | | |
| MasT | VA | Richmond | | | |
| MasT | CA | San Francisco | 1999 | | |
| MasT | Maine | | | | |
| MasT | NC | Triad | | | |
| MasT | AZ | Tucson | | | |
| Mates | MA | Providence | 1994 | Yes | |
| Mavericks | NM | Santa Fe | | | |
| MC Faucon Montreal | CAN | Montreal | | | |
| MC Keno | CAN | Montreal | 1970-11-01 00:00:00 | | |
| MC Milano | Germany | | | | |
| MC Rhone Alpes | FR | Lyon | | | |
| Mecs en Caoutchiuc | Fr | Dammie Les Lys | 1994 | | |
| Meitsters Der Manner | Fl | Orlando | 1977 | | |
| Melbourne Bondage Club | AU | Melbourne | 1990 | | |
| Melbourne Leather Men | AU | Melbourne | 1991 | | |
| Memphis Bears | | | | | |
| Memphis L/L Alliance | TN | Memphis | 1992 | | |
| Memphis Power Exchange | TN | Memphis | | | |
| Men Bound by Leather | CA | Los Angeles | | | |
| Men in Boots | CAN | Vancouver | 1985 | | |
| Men of Discipline | CA | San Francisco | | | |
| Men of Discipline | DC | Washington | | | |
| Men of Dungeons | | | | | |
| Men of Leather | TN | Memphis | | | |
| Men of Leather | AU | Melbourne | | | |
| Men Of Phoenix | Rhode Island | | 2003 | 2006 | |
| Men of Renowned Edgeplay (MORE) | Co | Denver | | | |
| Men of Rubber | IL | Chicago | 1996 | | |
| Men Shaving Men | CAN | Vancouver | 1989 | | |
| Menamore | NC | Wilmington | 1989 | January 23, 2007 | |
| Mens Club Arhus | Denmark | | 1978 | | |
| Men's Welcoming Committee | WA | Seattle | | | |
| Metro Bears | NY | New York | 1995 | | |
| Metro Leather Society | MI | Royal Oak | 1993 | | |
| Mi Chat Ohs | Ohio | | | | |
| Michigan Rope | MI | Detroit | | | |
| Mid America Fists in Action (MAFIA) | Il | Chicago | 1979 | | |
| Mid Michigan Bears | | | 1994 | | |
| Mid America Conference of Clubs (Originally Midwest) | IL | Chicago | 1973 | | |
| Midlands Power Exchange | SC | Columbia | | | |
| Midlands Communication Network | NE | Omaha | | | |
| Midnight Leather Club | NY | Penfield | | | |
| Midnight Police leather Society | NY | Rochester | 1988 | | |
| Midwest Bear Pack | IN | Indianapolis | | | |
| Mike's Men | MA | Boston | 1989 | | |
| Mile High Handballers | Colorado | | | | |
| Military & Police Uniform Association | CA | West Hollywood | | | |
| Militia MC | VA | Norfolk | 1975 | | |
| Milwaukee Bondage Club | WI | Milwaukee | 1990 | | |
| Milwaukee Knights | WI | Milwaukee | | | |
| Miners | Scotland | Grenock | | | |
| Mini Bikes MC | LA | New Orleans | 1975 | | |
| Minnesota Leather Den (women) | MN | Minneapolis | 1992 | 1996 Underground | |
| Minnesota Leather Encounter | MN | Minneapolis | 1992 | | |
| Minnesota Marauders | MN | Minneapolis | 1979 | | |
| Minnesota Norsemen | Minnesota | | 1975 | | |
| Minnesota Power Exchange | Minnesota | | | | |
| Minnesota Stocks, Debentures and Bonds (MSDB) | Minnesota | | 1999 | | |
| Minnesota Storm Patrol | MN | Minneapolis | 2003 | | |
| Minotaurs BC | NH | Concord | | | |
| Misfits | TX | Houston | 1992 | | |
| Mississippi Alternative Social Kinks (MASK) | Mississippi | | | | |
| Missouri Association of Clubs | Missouri | | 1977 | | |
| MLC Munchen | GER | Munchen | | | |
| MLC Veneto | Bedin | | | | |
| MLLA | FL | Lakeland | | | |
| MOB New England (women) | MA | Boston | | | |
| Mobile Man Van Club | Mi | Detroit | 1977 | | |
| Monterey Dons | California | | 1973 | | |
| Mooncussers MC | MA | Provincetown | | | |
| Moonlight Leather Association of the Deaf (MLAD) | CA | San Diego | 1991 | | |
| Moonshine Bears | Kentucky | | | | |
| Moor Cocks | New York | | 1985 | | |
| Mortifoto (scat) | Holland | Haag | | | |
| Motivation | England | | | | |
| Moto Leather Club Veneto | Italy | Veneto | | | |
| Motor City Bears | Mi | Detroit | 1989 | | |
| Motorcity Men of Leather | Mi | Detroit | 1989 | | |
| Motorcyclemen of New Mexico | NM | Albuquerque | 1981 | | |
| Mountain Men of Leather | Co | Denver | 1977 | | |
| Mountain State Bears | WV | Charleston | | | |
| Mountain State Knights | West Virginia | | | | |
| Moving Violations | MA | Boston | | | |
| MP Bands | CA | Canoga Park | | | |
| MPs Northeast | MA | Lowell | | | |
| MS Amsterdam | Amsterdam | | 1970 | | |
| MS Panther Cologne Germany | Germany | | 1974 | | |
| Ms Rocky Mountain Leather Association | CO | Denver | 1985 | 1986 | |
| MS Rotterdam | | | | | |
| MSC - MSC | England | | | | |
| MSC (SW) | netherlands | | | | |
| MSC Barcelona | England | | | | |
| MSC Belgica | Belgium | | 1971 | 1977 | |
| MSC Belgium | Belgium | | 1977 | | |
| MSC Berlin | GER | Berlin | 1974 | | |
| MSC Bournemouth | England | | | | |
| MSC East Mercia | Germany | | 1982 | | |
| MSC Finland | Finland | | 1976 | | |
| MSC Frankfurt | GER | Frankfurt | | | |
| MSC Groningen | Netherlands | | 1976 | | |
| MSC Hallanshire | England | | | | |
| MSC Hamburg | GER | Hamburg | 1974 | | |
| MSC Hannover | Germany | | | | |
| MSC Koln | | | | | |
| MSC Iceland | Iceland | | 1985 | | |
| MSC London | ENG | London | 1973 | | |
| MSC Madrid | Spain | | | | |
| MSC Midland Link | UK | Worchester | 1974 | | |
| MSC Northeast | England | | | | |
| MSC Northwest | England | | 1975 | | |
| MSC Pennine Chain | UK | Chesire | 1974 | | |
| MSC Rheim Main | Germany | | 1971 | | |
| MSC Rote Erde | | | | | |
| MSC Scotland | Scotland | | 1974 | | |
| MSC Solent | UK | SOlent | | | |
| MSC Southwest | | | | | |
| MSC Sudwest | Germany | | | | |
| MSC Suisse Romande | Lausanne | | 1981 | | |
| MSC Toronto | CAN | Toronto | | | |
| MSC Viking | Koln | | | | |
| Mud Buddies | CA | San Diego | | | |
| Mud Men (changed name to Sludgemasters) | TX | Houston | 1994 | | |
| Munchner Leder Club | NY | Nova | 1975 | | |
| Munich Bears | GER | Munich | | | |
| Munich Leather Club | GER | Munich | | | |
| Muscle Mates | NY | New York | | | |
| Music City Bears | TN | Nashville | | | |
| Mustang | TX | Houston | | | |
| Myrtle Beach Kink | NC | Myrtle Beach | | | |
| Mythos | CAN | Calgary | 2002 | | |