2003 Grand Prix de Tennis de Lyon – Singles

Paul-Henri Mathieu was the defending champion but lost in the first round to Rainer Schüttler.

Schüttler won in the final 7–5, 6–3 against Arnaud Clément.

Seeds

 * 1) 🇩🇪 Rainer Schüttler (champion)
 * 2) 🇫🇷 Sébastien Grosjean (first round)
 * 3) 🇹🇭 Paradorn Srichaphan (semifinals)
 * 4) 🇪🇸 Félix Mantilla (first round)
 * 5) 🇺🇸 Mardy Fish (first round)
 * 6)  Wayne Ferreira (first round)
 * 7) 🇷🇺 Marat Safin (first round)
 * 8) 🇷🇺 Yevgeny Kafelnikov (first round)