1920–21 National Challenge Cup
Dewar Challenge Cup  | |
| Tournament details | |
|---|---|
| Country | United States | 
| Dates | 16 October 1920- 19 April 1921  | 
| Defending champions | Ben Millers | 
| Final positions | |
| Champions | Robins Dry Dock (1st title) | 
| Runners-up | Scullin Steel | 
| Semifinalists | |
The 1920–21 National Challenge Cup was the annual open cup held by the United States Football Association now known as the Lamar Hunt U.S. Open Cup.