The 2004 Adidas International was a combine men's and women's tennis tournament played on outdoor hard courts at the NSW Tennis Centre in Sydney in Australia that was part of the International Series of the 2004 ATP Tour and of Tier II of the 2004 WTA Tour. The tournament ran from 11 through 18 January 2004. Lleyton Hewitt and Justine Henin-Hardenne won the singles titles.
See main article: 2004 Adidas International – Men's singles. Lleyton Hewitt defeated Carlos Moyá 4–3 (Moyá retired)
See main article: 2004 Adidas International – Women's singles. Justine Henin-Hardenne defeated Amélie Mauresmo 6–4, 6–4
See main article: 2004 Adidas International – Men's doubles. Jonas Björkman / Todd Woodbridge defeated Bob Bryan / Mike Bryan 7–6(7–3), 7–5
See main article: 2004 Adidas International – Women's doubles. Cara Black / Rennae Stubbs defeated Dinara Safina / Meghann Shaughnessy 7–5, 3–6, 6–4