John Arthur Lithgow (pron-en?l???o?, respellLITHgoe; born October 19, 1945) is an American actor, musician, and author. He works across a wide range of media, including stage, television, film, book author and radio.

Lithgow is known for his roles as Dr. Dick Solomon on the NBC sitcom 3rd Rock from the Sun, Arthur Mitchell on Showtimes Dexter (Dexter (TV series)) and Reverend Shaw Moore in Footloose (Footloose (1984 film)). He appeared in the films The World According to Garp (The World According to Garp (film)) (1982) and Terms of Endearment (1983), receiving the Academy Award nomination, Best Actor in a Supporting Role for each.

On the stage, he appeared in the musical adaptation of Sweet Smell of Success (Sweet Smell of Success (musical)), winning the Tony Award for Best Leading Actor in a Musical. He again appeared in a musical, Dirty Rotten Scoundrels (Dirty Rotten Scoundrels (musical)), receiving the Tony nomination for Best Leading Actor in a Musical.

He has also recorded music, such as the 1999 album of childrens music, Singin in the Bathtub, and has written poetry and short stories for children, such as Marsupial Sue.