| Tournament details | |
|---|---|
| Country | United States |
| Teams | 40 |
| Defending champions | D.C. United |
| Final positions | |
| Champions | Seattle Sounders FC (1st title) |
| Runner-up | D.C. United |
| 2010–11 CONCACAF Champions League | Seattle Sounders FC |
| Tournament statistics | |
| Matches played | 39 |
| Goals scored | 107 (2.74 per match) |
| Top goal scorer(s) | Taiwo Atieno Bryan Kanu Stephen King Sébastien Le Toux Keita Mandjou Randi Patterson Melvin Tarley (3 goals each) |
The 2009 Lamar Hunt U.S. Open Cup was the 96th edition of the USSF's annual national soccer championship, running from June through early September.
The tournament proper features teams from the top five levels of the American Soccer Pyramid. These five levels, namely Major League Soccer, the United Soccer Leagues (First Division, Second Division, and Premier Development League), and the United States Adult Soccer Association, each have their own separate qualification process to trim their ranks down to their final eight team delegations in the months leading up to the start of the tournament proper. The eight MLS clubs receive byes into the third round, while the remaining 32 teams play in the first two round with brackets influenced by geography.
Seattle Sounders FC defeated defending-champion D.C. United 2–1 in the final at RFK Stadium in Washington, D.C. Both clubs had started in the MLS qualification tourney, and ended up playing 6 matches each.