Wallace Michael Shawn (born November 12, 1943) is an American actor, voice actor, comedian, playwright and essayist. His film roles have included those of Wally Shawn in the Louis Malle directed comedy-drama My Dinner with Andre (1981), Vizzini in The Princess Bride (1987), Mr. James Hall in Clueless (1995) and providing the voice of Rex in the Toy Story franchise. He has also appeared in a variety of television series, including recurring roles as Grand Nagus Zek in Star Trek: Deep Space Nine (1993–1999) and Cyrus Rose in Gossip Girl (2008–2012).
His plays include Obie Award winning Aunt Dan and Lemon (1985), The Designated Mourner (1996) and Grasses of a Thousand Colors (2008). He also co-wrote the screenplay for My Dinner with Andre with Andre Gregory, and he scripted A Master Builder (2013), a film adaptation of the play by Henrik Ibsen, which he also starred in. His book Essays was published in 2009 by Haymarket Books.