The 2004 Madrid Masters (also known as the Mutua Madrileña Masters Madrid for sponsorship reasons) was a tennis tournament played on indoor hard courts. It was the 3rd edition of the Madrid Masters, and was part of the ATP Masters Series of the 2004 ATP Tour. It took place at the Madrid Arena in Madrid, Spain, from 18 October through 25 October 2004. Third-seeded Marat Safin won the singles title.
In the absence of world number one Roger Federer, the singles field was led by ATP no. 5, French Open and US Open semi-finalist, Wimbledon quarterfinalist and Indian Wells finalist Tim Henman, Cincinnati titlist, 2002 Madrid Masters winner, 2003 Masters Cup winner and eight-time grand slam champion Andre Agassi and Australian Open runner-up, Beijing titlist and Estoril finalist Marat Safin. Other top seeds were Rome Masters runner-up, 2002 Wimbledon Championships titlist David Nalbandian, Olympics gold medalist, Kitzbühel winner Nicolás Massú, Juan Carlos Ferrero, Joachim Johansson and Tommy Robredo.
See main article: 2004 Mutua Madrileña Masters Madrid – Singles. 
Marat Safin defeated 
David Nalbandian 6–2, 6–4, 6–3
See main article: 2004 Mutua Madrileña Masters Madrid – Doubles. Mark Knowles / 
Daniel Nestor defeated 
Bob Bryan / Mike Bryan 6–3, 6–4