2003 US Open – Men's singles

Andy Roddick defeated Juan Carlos Ferrero in the final, 6–3, 7–6(7–2), 6–3 to win the men's singles tennis title at the 2003 US Open. It was his first and only major title. Roddick remains the most recent American to win a major men's singles title. Roddick saved a match point en route to the title, in the semifinals against David Nalbandian. He also completed the "Summer Slam," having won Masters titles in Canada and Cincinnati in the lead-up to the US Open.

Pete Sampras was the reigning champion, but he retired from professional tennis in August 2003.

This tournament marked the first US Open main draw appearance for future four-time champion Rafael Nadal, as well as the first major main draw appearance for future world No. 4 and Wimbledon finalist Tomáš Berdych. It also marked the final major appearances for former major champions Michael Chang and Yevgeny Kafelnikov.

Seeds
• # 🇺🇸 Andre Agassi (semifinals)

• # 🇨🇭 Roger Federer (fourth round)

• # 🇪🇸 Juan Carlos Ferrero (final)

• # 🇺🇸 Andy Roddick (champion)

• # 🇦🇷 Guillermo Coria (quarterfinals)

• # 🇦🇺 Lleyton Hewitt (quarterfinals)

• # 🇪🇸 Carlos Moyà (fourth round)

• # 🇩🇪 Rainer Schüttler (fourth round)

• # 🇫🇷 Sébastien Grosjean (first round)

• # 🇨🇿 Jiří Novák (third round)

• # 🇹🇭 Paradorn Srichaphan (fourth round)

• # 🇳🇱 Sjeng Schalken (quarterfinals)

• # 🇦🇷 David Nalbandian (semifinals)

• # 🇧🇷 Gustavo Kuerten (first round)

• # 🇨🇱 Fernando González (third round)

• # 🇳🇱 Martin Verkerk (second round)

• # 🇪🇸 Tommy Robredo (first round)

• # 🇧🇾 Max Mirnyi (first round)

• # 🇦🇷 Agustín Calleri (second round)

• # 🇦🇺 Mark Philippoussis (third round)

• # 🇪🇸 Félix Mantilla (first round)

• # 🇲🇦 Younes El Aynaoui (quarterfinals)

• # 🇿🇦 Wayne Ferreira (second round)

• # 🇺🇸 Mardy Fish (second round)

• # 🇪🇸 Albert Costa (second round)

• # 🇦🇷 Mariano Zabaleta (first round)

• # 🇷🇺 Yevgeny Kafelnikov (third round)

• # 🇪🇸 Feliciano López (first round)

• # 🇦🇷 Gastón Gaudio (first round)

• # 🇫🇷 Arnaud Clément (second round)

• # 🇺🇸 Vincent Spadea (first round)

• # 🇦🇷 Juan Ignacio Chela (third round)