William George "Billy" Zane, Jr. (born February 24, 1966) is an American actor and director. He is best recognized for his role as Caledon Hockley in the 1997 blockbuster film Titanic, as the deranged psychopath Hughie Warriner in Dead Calm, John Justice Wheeler in Twin Peaks, as The Phantom in the 1996 eponymous film based upon the comic book superhero, and as Xehanort, the main antagonist of the Kingdom Hearts series. As of 2008, Zane has appeared in over 50 films and numerous TV-series.

Zane was born in Chicago, Illinois, the son of Thalia and William George Zane, Sr., both of whom were amateur actors and founders of a school for medical technicians. His family's original surname, "Zanikopolous", was anglicized to "Zane" by his grandparents. Both of his parents are of Greek descent. He has an older sister Lisa Zane, who is also an actress.

After completing a year abroad at the American School in Switzerland, Zane graduated from the Francis W. Parker School and attended Harand Camp of the Theater Arts, located in Wisconsin.