The 2003 WTA Tour Championships, also known by its sponsored name Bank of America WTA Tour Championships, was a women's tennis tournament played on indoor hard courts at the Staples Center in Los Angeles, United States.

First-seeded Kim Clijsters won the singles event and earned $1,000,030[a] first-prize money as well as 485 ranking points.

[2] With her victory Clijsters became the first female tennis player to earn $US4 million in a season.

[3] For the first time since 1978 a round robin system was used, after the men's Tennis Masters Cup.

Virginia Ruano Pascual / Paola Suárez defeated Kim Clijsters / Ai Sugiyama, 6–4, 3–6, 6–3.