He was born in White Plains, New York, the son of Kenneth Arthur (an automobile dealer) and Ruth (Roane) Billington.
Billington has 96 Broadway productions to his credit including Copperfield, Checking Out, Moon Over Buffalo, Grind, Hello Dolly!, Meet Me in St. Louis, On the Twentieth Century, Side by Side by Sondheim, Lettice and Lovage, Tru, The Scottsboro Boys, and Sweeney Todd.
Billington was the principal lighting designer for Radio City Music Hall from 1979 - 2004, where he created the lighting for the world-famous Christmas and Easter Spectaculars. While there, he also created the lighting for the stage adaptation of the 1937 animated musical film Snow White and the Seven Dwarfs. Other projects include lighting the 1975/76 season for the American Shakespeare Festival at Stratford, Connecticut as well as projects such as Turandot at the Vienna State Opera, to nightclub acts for headliners Ann-Margret, Shirley MacLaine, and Liberace.
At Disneyland, Billington's lighting is featured in the extravaganza Fantasmic. His architectural designs can be seen in restaurants and clubs from Manhattan to Asia. Ken also designed the lighting plot and original design for all four current Dolly Parton Dixie Stampede locations.
Billington has been nominated for the Tony Award for Best Lighting Design eight times and in 1997 won for the revival of Chicago, which also garnered him the Drama Desk Award for Outstanding Lighting Design.
In November 2015, Billington was inducted into the Theater Hall of Fame.