Rummikub (also known as Rummy-O, Rummycube, Rummyking Tile rummy and Rummy Tile) is a tile-based game for two to four players.

Rummikub was invented by Ephraim Hertzano, a Romanian-born Jew, who immigrated to Mandate Palestine in the early 1930s. He hand-made the first sets with his family in the backyard of his home. The game combines elements of rummy, dominoes, mah-jongg and chess. Hertzano sold the first sets door-to-door and on a consignment basis at small shops. Over the years, the family licensed it to other countries and it became Israel’s #1 export game. In 1977, it became a bestselling game in the United States.

Hertzano's 'Official Rummikub Book', published in 1978, describes three different versions of the game: American, Sabra and International. Modern Rummikub sets include only the Sabra version rules, with no mention of the others, and there are variations in the rules between publishers.

The game was first made by Lemada Light Industries Ltd, founded by Hertzano. "Six handed" (a game with 6 colors) is available in Germany. It tends to be more fun for larger parties, but less challenging, as it is much easier to make a set of 3 different colors when there are 6 available.