Robert Thomas Letterman is an American filmmaker. He made his directorial debut as co-director of the animated comedy film Shark Tale (2004), for which he received a nomination for the Annie Award for Writing in a Feature Production. He then co-directed the animated science fiction comedy film Monsters vs. Aliens (2009).

Shark Tale is a 2004 American animated comedy film produced by DreamWorks Animation. The film was directed by Vicky Jenson, Bibo Bergeron, and Rob Letterman, from a screenplay written by Letterman and Michael J. Wilson. The film features an ensemble cast that includes the voices of Will Smith, Robert De Niro, Renée Zellweger, Jack Black, Angelina Jolie, and Martin Scorsese. It tells the story of an underachieving fish named Oscar (Smith) who falsely claims to have killed the son of a shark mob boss Don Lino in an attempt to advance his community standing. Oscar teams up with the mobster's younger son Lenny (Black) to keep up the facade.