| Club: | Tacoma Defiance |
| Season: | 2021 |
| League: | USL Championship |
| Chrtitle: | General manager |
| Mgrtitle: | Head coach |
| Manager: | Wade Webber |
| Stadium: | Cheney Stadium |
| Cup1: | USL Playoffs |
| Highest Attendance: | League: 1,993 (9/22 v. SAC) |
| Lowest Attendance: | League: 811 (10/13 v. LV) |
| Average Attendance: | League: |
| Largest Win: | OC 0–3 TAC (8/18) TAC 4–1 OC (10/9) |
| Pattern B1: | _tac21h |
| Pattern Sh1: | _black_stripes_adidas |
| Leftarm1: | 3d4041 |
| Body1: | 3d4041 |
| Rightarm1: | 3d4041 |
| Shorts1: | 3d4041 |
| Socks1: | 3d4041 |
| Pattern B2: | _shoulder_stripes_black_stripes |
| Pattern Sh2: | _black_stripes_adidas |
| Pattern So2: | _3_stripes_black |
| Leftarm2: | FFFFFF |
| Body2: | FFFFFF |
| Rightarm2: | FFFFFF |
| Shorts2: | FFFFFF |
| Socks2: | FFFFFF |
| American: | true |
| Prevseason: | 2020 |
| Nextseason: | 2022 |
The 2021 Tacoma Defiance season was the seventh season of the Tacoma Defiance, an American soccer team that played in the USL Championship, the second tier of soccer in the country. It was the fourth season since the club was renamed from Seattle Sounders FC 2 and relocated to Tacoma, Washington. Defiance is majority owned by Seattle Sounders FC, a Major League Soccer team, and serves as their reserve and development squad.
See main article: 2021 USL Championship season.
See main article: 2021 U.S. Open Cup.
Due to their ownership by a higher division professional club (Seattle Sounders FC), Tacoma is one of 15 teams expressly forbidden from entering the Cup competition.[1]
Numbers after plus-sign(+) denote appearances as a substitute.