Alexander Ian Sharp (born 2 February 1989) is an English actor. He is known for originating the role of Christopher Boone in the Broadway production of The Curious Incident of the Dog in the Night-Time.

After graduating from the Juilliard School in the summer of 2014, he made his Broadway and acting debut in the play The Curious Incident of the Dog in the Night-Time in the autumn. For his role as the autistic teenager Christopher Boone, he was awarded the Tony Award for Best Actor in a Play, Drama Desk Award for Outstanding Actor in a Play, and the Outer Critics Circle Award.