Jung Ki-yeol (born December 5, 1981), known professionally as Kai, is a South Korean singer and musical theatre actor.
He is best known in musical theatre and has starred in Korean productions of A Tale of Two Cities, The Three Musketeers and Phantom.
Outside of musical theatre, Kai has appeared as a panelist on singing variety shows such as King of Mask Singer and was host of the classical music show ??? ?? ?? (Music of the World) on KBS Classic FM.