| Mariscal Sucre | — | — | 1925 | National Stadium of Peru |
| Maurolico Messina | — | — | — | — |
| Maxima Roma | Serie A | — | 2026 | Palazzo dello Sport |
| Mens Sana Basket | Serie A | सियेना | 1861 | Palasport Mens Sana |
| Merchants United Social, Sports and Cultural Association | Peruvian Primera División | — | 19 सितंबर 2002 | Juan Maldonado Gamarra Stadium |
| Meyana Mesagne | — | Mesagne | — | — |
| Miguel Grau de Abancay | Copa Perú | — | 1955 | Estadio Monumental de Condebamba |
| Milwaukee Braves | मेजर लीग बेसबॉल | मिल्वौकी | 1953 | Milwaukee County Stadium |
| Mina San Vicente | Copa Perú | — | जून 1970 | — |
| Minnesota North Stars | नैशनल हॉकी लीग | Bloomington | 1967 | Met Center |
| Minnesota United FC | मेजर लीग सॉकर | मिनियापोलिस | 2015 | Allianz Field, Huntington Bank Stadium |
| Miraflores Sporting Club | — | — | — | Estadio Nacional del Perú (1897) |
| Montigarda Basket | — | Montichiari | — | — |
| Montreal Expos | मेजर लीग बेसबॉल | — | 1969 | Olympic Stadium, Jarry Park Stadium |
| Montreal Maroons | — | — | 1924 | Montreal Forum |
| MTVB Herons Basket | — | Montecatini Terme | — | — |
| Napoli Basket | — | नेपल्स | 1978 | — |
| Napoli Basket Vomero | — | नेपल्स | 1986 | — |
| Napoli Basketball | — | नेपल्स | 2011 | — |
| Nashville SC | मेजर लीग सॉकर | नैशविले | 2017 | Geodis Park, एल पी फील्ड |
| NBA New Basket A-Zena | — | जेनोआ | — | — |
| New Basket Brindisi | Serie A | ब्रिंदिज़ी | 1992 | PalaPentassuglia |
| New Polibasket San Bonifacio | — | — | — | — |
| New York Giants | — | — | — | — |
| Nova Virtus Ragusa | — | रगूसा | — | — |
| NPC Rieti | — | Rieti | 2011 | — |
| Nuova Pallacanestro Gorizia | — | गोरिज़िया | 1934 | — |
| Nuova Pallacanestro Vigevano | — | Vigevano | 1955 | — |
| Octavio Espinosa de Ica | Copa Perú | — | 1923 | Estadio José Picasso Peratta |
| Oleggio Magic Basket | — | Oleggio | — | — |
| Olimpia Basket Matera | — | मटेरा | 1960 | — |
| Olimpia Basket Pistoia | — | Pistoia | 1965 | — |
| Olimpia Cagliari | — | काल्यारी | 1953 | — |
| Olimpia Milano | Serie A | मिलानो | 1936 | Forum di Milano |
| Olympia 68 Basketball | — | रेज्जो कालाब्रिया | — | — |
| Olímpico Peruano | Copa Perú | — | 2 फ़रवरी 1945 | — |
| Oratorio Elmas | — | — | — | — |
| Ottawa Senators | — | — | 1883 | — |
| Pallacanestro Ares Palermo | — | पलेर्मो | — | — |
| Pallacanestro Aurora Desio | — | Desio | 1994 | — |
| Pallacanestro Biella | — | बीएलला | 1994 | BiellaForum |
| Pallacanestro Broni 93 | — | — | — | — |
| Pallacanestro Cantù | Serie A | Cermenate | 1936 | Palasport Pianella |
| Pallacanestro Don Bosco Livorno | — | — | — | — |
| Pallacanestro Firenze | — | फ़्लोरेन्स | 1948 | — |
| Pallacanestro Forlì 2.015 | Serie A2 Basket | फोर्ली | 2015 | Unieuro Arena |
| Pallacanestro Gallaratese | — | — | — | — |
| Pallacanestro Interclub | — | — | — | — |