Sultan Yahya Petra ibni Almarhum Sultan Ibrahim was Sultan of Kelantan from 1960, and the sixth Yang di-Pertuan Agong, the constitutional monarch of Malaysia, from 1975, until his death in 1979.

The Sultan of Kelantan is the constitutional head of Kelantan state in Malaysia. The executive power of the state is vested in him as the monarch of the state. The current sultan, Muhammad V, is the 29th Sultan of Kelantan. He is the Head of Islam in the state and the source of all titles, honours and dignities of its people. He was the 15th Yang di-Pertuan Agong or the monarch and head of state of Malaysia from 13 December 2016 to his abdication on 6 January 2019, after his election on 14 October 2016 at the 243rd (special) Conference of Rulers.