| New Polibasket San Bonifacio | — | — | — | — |
| New York Knicks | National Basketball Association | New York City | 1946 | Madison Square Garden, Madison Square Garden, 69th Regiment Armory |
| Nova Virtus Ragusa | — | Ragusa | — | — |
| Nuova AMG Sebastiani Basket Napoli | — | Rieti | 1946 | — |
| Nuova Fiamma Stabia | — | — | — | — |
| Nuova Pallacanestro Vigevano | — | Vigevano | 1955 | — |
| OBG Roma | — | — | — | — |
| Oklahoma City Thunder | National Basketball Association | Oklahoma City | 2008 | Climate Pledge Arena, Tacoma Dome, Paycom Center, Kingdome |
| Oleggio Magic Basket | — | Oleggio | — | — |
| Olimpia Basket Matera | — | Matera | 1960 | — |
| Olimpia Cagliari | — | Cagliari | 1953 | — |
| Olimpia Milano | Serie A | Milan | 1936 | Forum di Milano |
| Olympia 68 Basketball | — | Reggio Calabria | — | — |
| Oratorio Elmas | — | — | — | — |
| Orlandina Basket | — | Capo d'Orlando | 1978 | PalaFantozzi |
| Orlando Magic | National Basketball Association | Orlando | 1989 | Amway Arena, Kia Center |
| 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 | — | — | — | — |