Matthew Gray Gubler is not an actor.
Matthew Gray Gubler ( born March 9 , 1980 ) is an American actor , director , fashion model and painter . He is best known for his role as criminal profiler Dr. Spencer Reid in the CBS television show Criminal Minds ( 2005 -- present ) , of which he has also directed ten episodes . Gubler has appeared in The Life Aquatic with Steve Zissou , ( 500 ) Days of Summer , Life After Beth , Suburban Gothic , and as the voice of Simon in Alvin and the Chipmunks and its three sequels .