The Reuben or Reuben sandwich is a grilled or toasted sandwich made with corned beef, sauerkraut, Swiss cheese, and Russian dressing. It is typically made with rye bread though originally it may have been served on pumpernickel bread.

The origins of the Reuben are contested. One account holds that Reuben Kulakofsky (sometimes spelled Reubin), a grocer from Omaha, Nebraska, was the inventor, perhaps as part of a group effort by members of Kulakofsky's weekly poker game held in the Blackstone Hotel from ca. 1920-1935. The participants, who nicknamed themselves "the committee," included the hotel's owner, Charles Schimmel.