Major General Tunku Ismail ibni Sultan Ibrahim is a member of the Johor royal family who is the Regent and Crown Prince of Johor as well as the heir apparent to the throne of Johor. He is the eldest son of Sultan Ibrahim and the Permaisuri of Johor Raja Zarith Sofiah. He is also the grandson of both Sultan Iskandar of Johor and Sultan Idris Shah II of Perak.

A crown prince or hereditary prince is the heir apparent to the throne in a royal or imperial monarchy. The female form of the title is crown princess, which may refer either to an heiress apparent or, especially in earlier times, to the wife of the person styled crown prince.