Widely known for his work directing his friend Lin-Manuel Miranda's works In the Heights and Hamilton. He won the 2016 Tony award for Best Direction of a Musical for his work on Hamilton's original Broadway run.
He graduated from Wesleyan University alongside Lin-Manuel Miranda in 1999. He co-founded the freestyle hip-hop group Freestyle Love Supreme with him while the two were underclassmen.
He served as the director for Fox's Grease: Live! 2016 TV event. He was nominated for two Emmy Awards for his work.
Kail and his wife Michelle Williams welcomed a child together in June 2020. He was previously married to theater actress Angela Christian.
He directed John Krasinski in the play Dry Powder, which premiered off-Broadway at the Public Theater in New York City, in 2016.