The 2004 Siebel Open was a tennis tournament played on indoor hard courts at the HP Pavilion at San Jose in San Jose, California in the United States that was part of the International Series of the 2004 ATP Tour. The tournament ran from February 9 through February 15, 2004.
Andy Roddick defeated Mardy Fish 7–6(15–13), 6–4
- It was Roddick's 1st title of the year and the 14th of his career.
James Blake / Mardy Fish defeated Rick Leach / Brian MacPhie 6–2, 7–5
- It was Blake's 1st title of the year and the 4th of his career. It was Fish's 1st title of the year and the 3rd of his career.