2003 NASDAQ-100 Open – Men's singles

Two-time defending champion Andre Agassi defeated Carlos Moyá in the final, 6–3, 6–3 to win the men's singles tennis title at the 2003 Miami Open.

Seeds
All thirty-two seeds received a bye to the second round. • # 🇦🇺 Lleyton Hewitt (second round)

• # 🇺🇸 Andre Agassi (champion)

• # 🇪🇸 Juan Carlos Ferrero (third round)

• # Roger Federer (quarterfinals)

• # 🇪🇸 Carlos Moyá (final)

• # 🇺🇸 Andy Roddick (third round)

• # 🇷🇺 Marat Safin (second round)

• # 🇨🇿 Jiří Novák (second round)

• # 🇪🇸 Albert Costa (semifinals)

• # 🇦🇷 David Nalbandian (third round)

• # 🇫🇷 Sébastien Grosjean (second round)

• # 🇩🇪 Rainer Schüttler (third round)

• # 🇹🇭 Paradorn Srichaphan (semifinals)

• # Sjeng Schalken (fourth round)

• # 🇧🇷 Gustavo Kuerten (second round)

• # 🇪🇸 Àlex Corretja (second round)

• # 🇦🇷 Gastón Gaudio (second round)

• # 🇬🇧 Tim Henman (second round)

• # 🇲🇦 Younes El Aynaoui (quarterfinals)

• # Fernando González (second round)

• # 🇺🇸 James Blake (third round)

• # 🇪🇸 Tommy Robredo (second round)

• # 🇷🇺 Mikhail Youzhny (second round)

• # 🇷🇺 Yevgeny Kafelnikov (third round)

• # 🇧🇪 Xavier Malisse (second round)

• # 🇦🇷 Guillermo Coria (fourth round)

• # Andrei Pavel (second round)

• # Marcelo Ríos (fourth round, withdrew because of a back injury)

• # Wayne Ferreira (third round)

• # 🇦🇷 Juan Ignacio Chela (third round)

• # 🇧🇾 Max Mirnyi (second round)

• # 🇫🇮 Jarkko Nieminen (third round)

Qualifying seeds
• # 🇸🇪 Jonas Björkman (qualified)

• # 🇸🇰 Karol Beck (qualified)

• # 🇵🇪 Luis Horna (qualified)

• # 🇧🇷 Flávio Saretta (qualifying competition, lucky loser)

• # 🇫🇷 Jean-René Lisnard (qualified)

• # 🇺🇸 Justin Gimelstob (qualifying competition)

• # 🇸🇪 Magnus Norman (qualifying competition)

• # 🇲🇦 Hicham Arazi (first round)

• # 🇦🇹 Jürgen Melzer (first round)

• # Irakli Labadze (qualifying competition)

• # 🇩🇪 Alexander Waske (first round)

• # 🇺🇸 Jeff Morrison (qualifying competition, retired)

• # Cecil Mamiit (qualifying competition)

• # 🇧🇪 Kristof Vliegen (qualifying competition)

• # Marc Rosset (first round)

• # 🇫🇷 Michaël Llodra (qualified)

• # 🇨🇿 Jan Vacek (qualified)

• # 🇵🇪 Iván Miranda (first round)

• # 🇦🇺 Scott Draper (first round)

• # 🇺🇸 Robert Kendrick (qualifying competition)

• # 🇧🇷 Ricardo Mello (first round)

• # 🇷🇺 Andrei Stoliarov (qualified)

• # 🇫🇷 Cyril Saulnier (qualified)

• # 🇧🇪 Christophe Rochus (qualified)

Qualifiers
• # 🇸🇪 Jonas Björkman

• # 🇸🇰 Karol Beck

• # 🇵🇪 Luis Horna

• # 🇫🇷 Michaël Llodra

• # 🇫🇷 Jean-René Lisnard

• # 🇨🇿 Jan Vacek

• # 🇧🇪 Christophe Rochus

• # 🇦🇺 Peter Luczak

• # 🇪🇸 Francisco Clavet

• # 🇷🇺 Andrei Stoliarov

• # 🇪🇸 Fernando Verdasco

• # 🇫🇷 Cyril Saulnier

Lucky loser

 * 1) 🇧🇷 Flávio Saretta