The 2003 U.S. Men's Clay Court Championships was a men's tennis tournament played on outdoor clay courts at the Westside Tennis Club in Houston, Texas in the United States and was part of the International Series of the 2003 ATP Tour.

It was the 35th edition of the tournament and ran from April 21 through April 27, 2003.

First-seeded Andre Agassi won the singles title.

Andre Agassi defeated Andy Roddick 3–6, 6–3, 6–4 Mark Knowles / Daniel Nestor defeated Jan-Michael Gambill / Graydon Oliver 6–4, 6–3