Monkey Business is a 1931 comedy film. It is the third of the Marx Brothers’ released movies, and the first not to be an adaptation of one of their Broadway shows. The film stars the four brothers: Groucho Marx, Chico Marx, Harpo Marx, and Zeppo Marx, and screen comedienne Thelma Todd. It is directed by Norman Z. McLeod with screenplay by S. J. Perelman and Will B. Johnstone. The story takes place in large part on an ocean liner crossing the Atlantic Ocean.