The year 2003 was the 11th year in the history of the Ultimate Fighting Championship (UFC), a mixed martial arts promotion based in the United States. In 2003, the UFC held five events beginning with UFC 41: Onslaught.
^ For the UFC Light Heavyweight Championship. Couture won via TKO (punches) at 2:39 of Round 3. Couture becomes the Interim Light Heavyweight Champion, and the first person to win a title in two different weight divisions (Couture was a two-time Heavyweight Champion).
^ For the UFC Lightweight Championship. Penn and Uno fought to a split draw after five rounds. Judges scored the bout 48–47 Uno, 48–46 Penn, and 48–48. This match was the final match of a 4-man tournament that took place over several cards to crown a new lightweight champion, the first round occurred on UFC 39. Without a definite outcome, the title remained vacant and eventually put the Lightweight division on hiatus. The Lightweight championship would be contested once again at UFC 64 and since then has become a permanent fixture in the UFC.