The 2004 NASDAQ-100 Open was a tennis tournament played on outdoor hard courts. It was the 20th edition of the Miami Masters and was part of the Masters Series of the 2004 ATP Tour and of Tier I of the 2004 WTA Tour. Both the men's and women's events took place at the Tennis Center at Crandon Park in Key Biscayne, Florida in the United States from March 24 through April 4, 2004.

The men's tournament was notable as it featured the first meeting between Roger Federer and Rafael Nadal, with Nadal winning in straight sets. The women’s tournament was also notable for featuring the first meeting between Maria Sharapova and Serena Williams, with Williams winning in straight sets.

Andy Roddick defeated Guillermo Coria 6–7^(2–7), 6–3, 6–1 (Coria retired)

Serena Williams defeated Elena Dementieva 6–1, 6–1

Wayne Black / Kevin Ullyett defeated Jonas Björkman / Todd Woodbridge 6–2, 7–6^(14–12)

Nadia Petrova / Meghann Shaughnessy defeated Svetlana Kuznetsova / Elena Likhovtseva 6–2, 6–3