Defending champion Kim Clijsters successfully defended her title, defeating Amélie Mauresmo in the final, 6–2, 6–0 to win the singles title at the 2003 WTA Tour Championships. It was her second Tour Finals title, her ninth title of the season, and the 19th of her career.

Note:

• Serena Williams had qualified but pulled out due to left knee surgery.
• Lindsay Davenport had qualified but pulled out due to left foot surgery.
• Venus Williams had qualified but pulled out due to abdominal injury.

	Semifinals							Final
	1	Kim Clijsters	4	6	6
	3	Jennifer Capriati	6	3	0
								1	Kim Clijsters	6	6
								4	Amélie Mauresmo	2	0
	4	Amélie Mauresmo	77	3	6
	2	Justine Henin-Hardenne	62	6	3

		Clijsters	Mauresmo	Dementieva	Rubin	RR W–L	Set W–L	Game W–L	Standings
1	Kim Clijsters		3–6, 6–4, 6–4	6–2, 6–2	6–4, 6–4	3–0	6–1 (86%)	39–26 (60%)	1
4	Amélie Mauresmo	6–3, 4–6, 4–6		6–3, 6–2	6–4, 4–6, 2–6	1–2	4–4 (50%)	38–36 (51%)	2
6	Elena Dementieva	2–6, 2–6	3–6, 2–6		4–6, 7–5, 6–1	1–2	2–5 (29%)	26–36 (42%)	4
7	Chanda Rubin	4–6, 4–6	4–6, 6–4, 6–2	6–4, 5–7, 1–6		1–2	3–5 (38%)	36–41 (47%)	3

Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-players-ties, head-to-head records; 4. in three-players-ties, percentage of sets won, or of games won; 5. steering-committee decision.

		Henin-Hardenne	Capriati	Myskina	Sugiyama	RR W–L	Set W–L	Game W–L	Standings
2	Justine Henin-Hardenne		6–2, 6–1	7–5, 5–7, 7–5	2–6, 4–6	2–1	4–3 (57%)	37–32 (54%)	1
3	Jennifer Capriati	2–6, 1–6		7–5, 5–7, 6–4	7–5, 7–6(7–3)	2–1	4–3 (57%)	35–39 (47%)	2
5	Anastasia Myskina	5–7, 7–5, 5–7	5–7, 7–5, 4–6		6–4, 6–3	1–2	4–4 (50%)	45–44 (51%)	3
8	Ai Sugiyama	6–2, 6–4	5–7, 6–7(3–7)	4–6, 3–6		1–2	2–4 (33%)	30–32 (48%)	4

Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-players-ties, head-to-head records; 4. in three-players-ties, percentage of sets won, or of games won; 5. steering-committee decision.

• WTA Tour Championships appearances