| Date: | August 1–8 |
| Edition: | 42nd |
| Category: | ATP World Tour 500 |
| Draw: | 48S / 16D |
| Prize Money: | $1,165,500 |
| Surface: | Hard / outdoor |
| Location: | Washington, D.C., United States |
| Champs: |  David Nalbandian[1] |
| Champd: |  Mardy Fish / Mark Knowles[2] |
| Main Name: | Washington Open (tennis) Washington Open |
The 2010 Legg Mason Tennis Classic was a tennis tournament played on outdoor hard courts. It was the 42nd edition of this event and was part of the ATP World Tour 500 series of the 2010 ATP World Tour. It took place at the William H.G. FitzGerald Tennis Center in Washington, D.C., USA, from August 1 through August 8, 2010. Unseeded David Nalbandian, who entered the main draw on a wildcard, won the singles title.[3]
List of Association of Tennis Professionals (ATP) singles entrants, as of July 26, 2010.
| Country | Player | Rank | Seed | |
|---|---|---|---|---|
 Czech Republic | 8 | 1 | ||
| 9 | 2 | |||
 Spain | 10 | 3 | ||
| 13 | 4 | |||
| 19 | 5 | |||
| 20 | 6 | |||
| 24 | 7 | |||
 Cyprus | 26 | 8 | ||
| 28 | 9 | |||
| Czech Republic | 29 | 10 | ||
 Australia | 30 | 11 | ||
 France | 32 | 12 | ||
| France | 33 | 13 | ||
| France | 34 | 14 | ||
| 35 | 15 | |||
 Kazakhstan | 37 | 16 |
The following players received wildcards into the singles main draw
The following players received entry from the qualifying draw:
See main article: 2010 Legg Mason Tennis Classic – Singles. David Nalbandian defeated Marcos Baghdatis, 6–2, 7–6(7–4)
See main article: 2010 Legg Mason Tennis Classic – Doubles. Mardy Fish / Mark Knowles defeated Tomáš Berdych / Radek Štěpánek, 4–6, 7–6(9–7), [10–7]
