The 2003 Gerry Weber Open was a men's tennis tournament played on grass courts at the Gerry Weber Stadion in Halle, North Rhine-Westphalia in Germany that was part of the International Series of the 2003 ATP Tour.

It was the 11th edition of the tournament and was held from 9 June until 15 June 2003.

First-seeded Roger Federer won the singles title.

Roger Federer defeated Nicolas Kiefer 6–1, 6–3 Jonas Björkman / Todd Woodbridge defeated Martin Damm / Cyril Suk 6–3, 6–4