UFC 41: Onslaught was a mixed martial arts event held by the Ultimate Fighting Championship on February 28, 2003, at the Boardwalk Hall in Atlantic City, New Jersey.

The event was broadcast live on pay-per-view in the United States, and later released on DVD.

The event also marked the return of Tank Abbott to the UFC.

Ken Shamrock served as the color commentator for this card.

Penn and Caol Uno had a split draw.