| Oratorio Elmas | — | — | — | — |
| Orlandina Basket | — | Capo d'Orlando | 1978 | PalaFantozzi |
| Orlando City SC | Major League Soccer | Orlando | 2013 | Inter&Co Stadium, Camping World Stadium |
| Orlando Magic | National Basketball Association | Orlando | 1989 | Amway Arena, Kia Center |
| Ottawa Senators | — | Kanata | 1992 | Canadian Tire Centre, TD Place Arena |
| Ottawa Senators | — | — | 1883 | — |
| Pallacanestro Ares Palermo | — | Palermo | — | — |
| Pallacanestro Aurora Desio | — | Desio | 1994 | — |
| Pallacanestro Biella | — | Biella | 1994 | BiellaForum |
| Pallacanestro Brindisi | — | Brindisi | 1945 | PalaPentassuglia |
| Pallacanestro Broni 93 | — | — | — | — |
| Pallacanestro Cantù | Serie A | Cermenate | 1936 | Palasport Pianella |
| Pallacanestro Chieti | — | Chieti | 1989 | — |
| Pallacanestro Interclub | — | — | — | — |
| Pallacanestro Lago Maggiore | — | — | — | — |
| Pallacanestro Livorno | — | Livorno | — | — |
| Pallacanestro Lucca | — | Lucca | — | — |
| Pallacanestro Marsala | — | — | — | — |
| Pallacanestro Messina | — | Messina | 1976 | — |
| Pallacanestro Olimpia La Spezia | — | La Spezia | 1969 | — |
| Pallacanestro Patti | — | — | — | — |
| Pallacanestro Pavia | — | Pavia | 1943 | — |
| Pallacanestro Petrarca Padova | — | Padua | 1934 | — |
| Pallacanestro Piacentina | — | Piacenza | 2011 | — |
| Pallacanestro Pozzuoli | — | — | — | — |
| Pallacanestro Reggiana | Serie A | Reggio Emilia | 1974 | PalaBigi |
| Pallacanestro Ribera | — | — | 1969 | — |
| Pallacanestro Ruvo di Puglia | — | — | — | — |
| Pallacanestro Sanga Milano | — | Milan | — | — |
| Pallacanestro Sant'Antimo | — | Sant'Antimo | 1989 | — |
| Pallacanestro Treviso | Serie A | Treviso | 1954 | Palaverde |
| Pallacanestro Varese | Serie A | Varese | 1945 | PalaWhirlpool |
| Pallacanestro Vicenza | — | Vicenza | — | — |
| Pallacanestro Virtus Cassino | — | Frosinone | 2011 | — |
| Pallalcesto Amatori Udine | inactive | Udine | 1944 | Palasport Primo Carnera |
| Palmares Catania | — | Catania | — | — |
| Pantere Basket Femminile | — | — | — | — |
| Partenio Avellino | — | — | — | — |
| Partenope Napoli | — | Sant'Antimo | 1957 | — |
| PB63 Lady | — | — | 1963 | — |
| PCR Messina | — | Messina | — | — |
| Pedro Anselmo Bazalar | Copa Perú | — | July 9, 2003 | Estadio Segundo Aranda Torres |
| Perugia Basket | — | — | — | — |
| Philadelphia 76ers | National Basketball Association | Philadelphia | 1946 | Xfinity Mobile Arena, Toyota Coliseum, Philadelphia Arena, Spectrum, Philadelphia Convention Hall and Civic Center, Oncenter War Memorial Arena |
| Philadelphia Athletics | — | — | 1901 | — |
| Philadelphia Eagles | National Football League | Philadelphia | 1933 | Lincoln Financial Field |
| Philadelphia Flyers | — | — | 1967 | Spectrum, Xfinity Mobile Arena |
| Philadelphia Phillies | Major League Baseball | Philadelphia | 1883 | Citizens Bank Park |