The 2005 Gerry Weber Open was a men's tennis tournament played on outdoor grass courts. It was the 13th edition of the Gerry Weber Open, and was part of the International Series of the 2005 ATP Tour. It took place at the Gerry Weber Stadion in Halle, North Rhine-Westphalia, Germany, from 6 June through 12 June 2005. First-seeded Roger Federer won his third consecutive singles title at the event.

Finals

Singles

Roger Federer defeated 🇷🇺 Marat Safin, 6–4, 6–7(6–8), 6–4

Doubles

Yves Allegro / Roger Federer defeated 🇸🇪 Joachim Johansson / 🇷🇺 Marat Safin, 7–5, 6–7(6–8), 6–3