Yup, and did his undergraduate studies at Princeton.Justin said:David Duchovny has a graduate degree in English Lit from Yale.
Masi Oka, the actor who plays Hiro Nakamura in Heroes, has a BS in computer science and maths from Brown. When he's not acting, he works as a digital effects artist. His digital work appears in such films as SW I, II and III, Pirates of the Caribbean: Dead Man's Chest and Terminator 3.
I don't know if John Astin who played Gomez in the original Addams Family TV series counts as a celebrity, but if he does, he desrves a mention. He studied at Johns Hopkins and teaches there now.
Wes Craven is also a Hopkins graduate.