See main article: 2003 Italian Open (tennis).
Kim Clijsters defeated Amélie Mauresmo in the final, 3–6, 7–6(7–3), 6–0 to win the women's singles tennis title at the 2003 Italian Open. It was her third title of the season, and the 13th overall in her career.
Serena Williams was the defending champion, but lost in semifinals to Mauresmo.
The first eight seeds received a bye into the second round.