For the 2021-22 season, Division III realigned basketball into 10 regions. Region 3 is a mix of teams from the former Atlantic and East regions. To find former East Region teams such as the United East, as well as former Atlantic Region teams from the CUNYAC, MAC Freedom and NJAC, check out Region 4.
| School | Location | Conference | Enrollment |
| Alfred | Alfred, NY | E8 | 1586 |
| Bard | Annandale-on-Hudson, NY | LL | 1698 |
| Brockport | Brockport, NY | SUNYAC | 6304 |
| Buffalo State | Buffalo, NY | SUNYAC | 8278 |
| Clarkson | Potsdam, NY | LL | 2579 |
| Cortland | Cortland, NY | SUNYAC | 6203 |
| Elmira | Elmira, NY | E8 | 1195 |
| Farmingdale State | Farmingdale, NY | SKY | 4455 |
| Fredonia | Fredonia, NY | SUNYAC | 4795 |
| Hartwick | Oneonta, NY | E8 | 1427 |
| Houghton | Houghton, NY | E8 | 1084 |
| Ithaca | Ithaca, NY | LL | 5932 |
| Keuka | Keuka Park, NY | E8 | 1033 |
| Manhattanville | Purchase, NY | SKY | 1528 |
| Merchant Marine | Kings Point, NY | SKY | 968 |
| Mount St. Mary | Newburgh, NY | SKY | 1563 |
| Mount St. Vincent | Riverdale, NY | SKY | 1310 |
| Nazareth | Rochester, NY | E8 | 1864 |
| Oswego State | Oswego, NY | SUNYAC | 6832 |
| Plattsburgh State | Plattsburgh, NY | SUNYAC | 5028 |
| Rochester Tech | Rochester, NY | LL | 12373 |
| Rochester | Rochester, NY | UAA | 5081 |
| RPI | Troy, NY | LL | 5357 |
| Sage | Troy, NY | E8 | 1252 |
| Sarah Lawrence | Bronxville, NY | SKY | 1314 |
| Skidmore | Saratoga Springs, NY | LL | 2249 |
| St. John Fisher | Pittsford, NY | E8 | 2660 |
| St. Joseph's (L.I.) | Patchogue, NY | SKY | 2487 |
| St. Joseph's (Bklyn.) | Brooklyn, NY | SKY | 829 |
| St. Lawrence | Canton, NY | LL | 2187 |
| SUNY Geneseo | Geneseo, NY | SUNYAC | 5414 |
| SUNY New Paltz | New Paltz, NY | SUNYAC | 6050 |
| SUNY Oneonta | Oneonta, NY | SUNYAC | 5711 |
| SUNY Potsdam | Potsdam, NY | SUNYAC | 3573 |
| SUNY-Old Westbury | Old Westbury, NY | SKY | 2340 |
| SUNY-Purchase | Purchase, NY | SKY | 3174 |
| Union | Schenectady, NY | LL | 2192 |
| Utica | Utica, NY | E8 | 2032 |
| Vassar | Poughkeepsie, NY | LL | 2377 |
| William Smith | Geneva, NY | LL | 2209 (with Hobart) |
| Yeshiva | New York, NY | SKY | 1215 |