2003 Campionati Internazionali di Sicilia – Singles

Fernando González was the defending champion but did not compete that year.

Nicolás Massú won in the final 1–6, 6–2, 7–6(7–0) against Paul-Henri Mathieu.

Seeds
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.


 * 1)  Nicolás Massú (champion)
 * 2) 🇷🇺 Nikolay Davydenko (first round)
 * 3) 🇪🇸 David Sánchez (first round)
 * 4) 🇮🇹 Filippo Volandri (second round)
 * 5) 🇫🇷 Paul-Henri Mathieu (final)
 * 6) 🇪🇸 Alberto Martín (semifinals)
 * 7) 🇪🇸 Rubén Ramírez Hidalgo (first round)
 * 8) 🇵🇪 Luis Horna (semifinals)