Defending champion Serena Williams defeated Jennifer Capriati in a rematch of the previous year's final, 4–6, 6–4, 6–1 to win the women's singles tennis title at the 2003 Miami Open.

Seeds

All seeds received a bye into the second round.

Draw

Finals

Top half

Section 1

Section 2

Section 3

Section 4

Bottom half

Section 5

Section 6

Section 7

Section 8

Qualifying

Qualifying seeds

• # 🇭🇺 Petra Mandula (first round) • # 🇪🇸 Marta Marrero (qualified) • # 🇦🇺 Evie Dominikovic (qualifying competition, lucky loser) • # 🇸🇪 Åsa Svensson (qualified) • # 🇪🇸 María Sánchez Lorenzo (qualified) • # Dally Randriantefy (first round) • # Rossana de los Ríos (first round) • # 🇫🇷 Marion Bartoli (qualified) • # 🇩🇪 Marlene Weingärtner (qualified) • # Jelena Kostanić (qualifying competition) • # 🇺🇸 Ashley Harkleroad (qualifying competition) • # 🇷🇺 Evgenia Kulikovskaya (first round) • # 🇫🇷 Stéphanie Cohen-Aloro (first round) • # 🇯🇵 Saori Obata (first round) • # 🇸🇰 Martina Suchá (first round) • # 🇨🇿 Libuše Průšová (first round) • # 🇺🇸 Lindsay Lee-Waters (qualifying competition) • # 🇺🇸 Ansley Cargill (qualifying competition) • # 🇷🇺 Nadia Petrova (qualifying competition) • # 🇺🇸 Samantha Reeves (first round) • # 🇻🇪 Milagros Sequera (first round) • # 🇸🇰 Ľubomíra Kurhajcová (qualifying competition) • # 🇨🇦 Maureen Drake (qualifying competition) • # Wynne Prakusya (first round)

Qualifiers

• # 🇺🇸 Mashona Washington • # 🇪🇸 Marta Marrero • # 🇱🇺 Claudine Schaul • # 🇸🇪 Åsa Svensson • # 🇪🇸 María Sánchez Lorenzo • # Jelena Janković • # 🇷🇺 Vera Dushevina • # 🇫🇷 Marion Bartoli • # 🇩🇪 Marlene Weingärtner • # 🇺🇦 Tatiana Perebiynis • # 🇷🇺 Anastasia Rodionova • # 🇨🇦 Marie-Ève Pelletier

Lucky loser

Qualifying draw

First qualifier

Second qualifier

Third qualifier

Fourth qualifier

Fifth qualifier

Sixth qualifier

Seventh qualifier

Eighth qualifier

Ninth qualifier

Tenth qualifier

Eleventh qualifier

Twelfth qualifier