William Gaither "Billy" Crudup is an American actor. He is known for his role in Gypsy, and supporting roles in films including Almost Famous, Big Fish, Mission: Impossible III, Watchmen, Public Enemies, Spotlight, and Alien: Covenant, as well as lead roles in films including Without Limits, Dedication, The Stanford Prison Experiment, and the animated film Princess Mononoke. He appeared in the 2017 superhero film Justice League as Doctor Henry Allen.
He has also had an extensive stage acting career, appearing mostly on Broadway.