| Los Angeles Football Club | Major League Soccer | Los Angeles | 2014 | BMO Stadium |
| Los Angeles Galaxy | Major League Soccer | Los Angeles | 1995 | Dignity Health Sports Park |
| Los Angeles Kings | — | Los Angeles, Inglewood | 1967 | Crypto.com Arena, Kia Forum |
| Los Angeles Raiders | National Football League | Los Angeles | 1982 | — |
| Los Angeles Rams | National Football League | — | 1936 | Edward Jones Dome, Angel Stadium, Los Angeles Memorial Coliseum, SoFi Stadium |
| Los Caimanes de Puerto Etén | Segunda División (Campeonato Peruano de Futebol) | — | 22 de maio de 1957 | Estadio César Flores Marigorda |
| Los Espartanos de Pacasmayo | Copa Peru | — | 1924 | — |
| Los Inseparables Sports and Cultural Club | Copa Peru | — | — | Juan Maldonado Gamarra Stadium |
| Magika Pallacanestro | — | Castel San Pietro Terme | — | — |
| Magnolia Basket Campobasso | — | Campobasso | 2017 | — |
| Mariscal Miller | Copa Peru | — | — | Estádio Jorge Basadre |
| Mariscal Nieto de Ilo | Copa Peru | — | — | Estadio Mariscal Nieto |
| Mariscal Sucre | — | — | 1925 | Estádio Nacional do Peru |
| Maurolico Messina | — | — | — | — |
| Maxima Roma | Liga Italiana de Basquetebol | — | 2026 | PalaLottomatica |
| Memphis Grizzlies | National Basketball Association | Memphis | 1995 | Pyramid Arena, FedExForum |
| Mercede Basket Alghero | — | Alghero | 1977 | — |
| Meyana Mesagne | — | Mesagne | — | — |
| Miami Dolphins | National Football League | Miami | 1966 | Hard Rock Stadium |
| Miami Heat | National Basketball Association | Miami | 1988 | Miami Arena, Kaseya Center |
| Miami Marlins | Major League Baseball | — | 1993 | LoanDepot Park, Hard Rock Stadium |
| Miguel Grau de Abancay | Copa Peru | — | 1955 | Estadio Monumental de Condebamba |
| Milwaukee Braves | Major League Baseball | Milwaukee | 1953 | Milwaukee County Stadium |
| Milwaukee Brewers | Major League Baseball | Milwaukee | 1969 | American Family Field |
| Milwaukee Bucks | National Basketball Association | Milwaukee | 1968 | UW–Milwaukee Panther Arena, Bradley Center, Fiserv Forum |
| Mina San Vicente | Copa Peru | — | junho 1970 | — |
| Minnesota North Stars | — | Bloomington | 1967 | Met Center |
| Minnesota Timberwolves | National Basketball Association | Minneapolis | 1989 | Hubert H. Humphrey Metrodome, Target Center |
| Minnesota Twins | Major League Baseball | — | 1901 | Target Field, American League Park, Metropolitan Stadium, Hubert H. Humphrey Metrodome, Boundary Field, Griffith Stadium |
| Minnesota United FC | Major League Soccer | Minneapolis | 2015 | Allianz Field, TCF Bank Stadium |
| Minnesota Vikings | National Football League | Minnesota | 1961 | Metropolitan Stadium, TCF Bank Stadium, Hubert H. Humphrey Metrodome, U.S. Bank Stadium |
| Minnesota Wild | — | Saint Paul | 2000 | Grand Casino Arena |
| Miraflores Sporting Club | — | — | — | Estadio Nacional del Perú (1897) |
| Modena Basket | — | — | — | — |
| Montigarda Basket | — | Montichiari | — | — |
| Montreal Expos | Major League Baseball | — | 1969 | Estádio Olímpico de Montreal, Jarry Park Stadium |
| Montreal Maroons | — | — | 1924 | Montreal Forum |
| MTVB Herons Basket | — | Montecatini Terme | — | — |
| Napoli Basket | Liga Italiana de Basquetebol | Nápoles | 2016 | PalaBarbuto |
| Napoli Basket Vomero | — | Nápoles | 1986 | — |
| Napoli Basketball | — | Nápoles | 2011 | — |
| Nashville Predators | — | — | 1998 | Bridgestone Arena |
| Nashville Soccer Club | Major League Soccer | Nashville | 2017 | Nashville Fairgrounds Stadium, Nissan Stadium |
| New Basket Palestrina | — | — | — | — |
| New England Patriots | National Football League | Foxborough | 1959 | Gillette Stadium |
| New England Revolution | Major League Soccer | Foxborough | 1995 | Gillette Stadium |
| New Jersey Devils | — | Newark, East Rutherford | 1974 | Izod Center, Prudential Center |
| New Orleans Pelicans | National Basketball Association | Nova Orleães | 2002 | Paycom Center, Smoothie King Center |