William Roscoe Leake (April 12, 1961 – September 2, 2006), better known as Willi Ninja, was an American dancer and choreographer known for his appearance in the documentary film Paris Is Burning.

Born at Long Island Jewish Medical Center in New Hyde Park, New York, Willi was a self-taught dancer and was perfecting his voguing style by his twenties.

Willi was born to a black mother and was of mixed racial ancestry, claiming to have Irish, Cherokee, and Asian ancestors.

His influences included Kemetic hieroglyphics, young Michael Jackson, Fred Astaire, Olympic gymnasts, and Asian culture.

Ninja's later career included runway modeling for Jean-Paul Gaultier, performing with dance companies under Karole Armitage, and providing instruction to Paris Hilton on perfecting her walk.

Ninja also danced in two of Janet Jackson's videos from her album Rhythm Nation 1814, one of which was "Alright", whose remix featured late rap star Heavy D and cameo appearances by Cab Calloway, Cyd Charisse, and The Nicholas Brothers.

On August 8, 1991, he was a guest on The Joan Rivers Show[6] alongside some of his Paris Is Burning cast members, such as Dorian Corey and Pepper LaBeija.