Wallace Michael Shawn (born November 12, 1943) is an American actor, voice artist, comedian, playwright and essayist. His film roles have included those of Wally Shawn in the Louis Malle-directed drama My Dinner with Andre, Vizzini in The Princess Bride (1987), Mr. James Hall in Clueless and the voice of Principal Mazur in A Goofy Movie and Rex in the Toy Story franchise. He has also had roles in six of Woody Allen's films. His television work includes recurring roles as Grand Nagus Zek in Star Trek: Deep Space Nine, Cyrus Rose in Gossip Girl, and Dr. John Sturgis in Young Sheldon.
His plays include Obie Award-winning Aunt Dan and Lemon, The Designated Mourner and Grasses of a Thousand Colors. He also co-wrote the screenplay for My Dinner with Andre with Andre Gregory, and scripted A Master Builder, a film adaptation of the play by Henrik Ibsen, in which he also starred. His book Essays was published in 2009 by Haymarket Books.
In Big City Greens, he played the voice of the antagonist Jyle Donelan in the episode "Night Bill".