| Date: | July 31 – August 6 |
| Edition: | 37th |
| Category: | International Series |
| Prize Money: | $575,000 |
| Draw: | 64S / 16D |
| Surface: | Hard / Outdoor |
| Venue: | William H.G. FitzGerald Tennis Center |
| Location: | Washington, D.C., United States |
| Champs: |  Arnaud Clément[1] |
| Champd: |  Bob Bryan / Mike Bryan[2] |
| Main Name: | Washington Open (tennis) Washington Open |
The 2006 Legg Mason Tennis Classic was the 37th edition of this men's tennis tournament and was played on outdoor hard courts. The tournament was part of the International Series of the 2006 ATP Tour. It was held at the William H.G. FitzGerald Tennis Center in Washington, D.C. in the United States from July 31 through August 6, 2006. Eleventh-seeded Arnaud Clément won the singles title.
See main article: article and 2006 Legg Mason Tennis Classic – Singles. Arnaud Clément defeated 
Andy Murray, 7–6(7–3), 6–2
See main article: article and 2006 Legg Mason Tennis Classic – Doubles. Bob Bryan / Mike Bryan defeated 
Paul Hanley / Kevin Ullyett, 6–3, 5–7, [10–3]