William Kemp is an English actor and dancer. He was born in Hertfordshire, England, the son of Rosi, a former model, and Barry Kemp, a graphic designer. He has been dancing since he was nine, with the encouragement of his mother. Trained at the Royal Ballet School, at age 17 he was accepted at the dance company Adventures in Motion Pictures (AMP). His most prestigious ballet accomplishment thus far was winning the lead role of The Swan in the all male cast of Swan Lake from 1997 to 2000 in both London and Broadway.

In 2002 he could be seen dancing to Stuff Like That in a Peter Lindbergh-directed commercial for Gap's "For Every Generation" campaign and in 2004 he appeared alongside Sarah Jessica Parkerin two Francis Lawrence-directed spots, "Color" and "Shine", for Gap's "How Do You Share It" campaign. He famously turned down a lucrative modelling contract with Giorgio Armani, citing not wanting to be confused to a model as opposed to an actor.

Kemp made his acting debut in 2004's Van Helsing, opposite Hugh Jackmanand Kate Beckinsale He played the horse Nugget as well as The Young Horseman in the 2007 West End revival of Equus starring Daniel Radcliffe. The part of Nugget required him to don a wire horse mask and metal hooves/horseshoes, and carry Daniel Radcliffe on his back whilst galloping. He also had a role in Step Up 2 the Streets as Blake Collins, director of the Maryland School of the Arts.