Tunku Ismail was born on 28 October 1894 at Istana Semayam, Johor Bahru and was the second and eldest surviving son of Tunku Ibrahim (later Sultan Ibrahim) by his first wife, Sultanah Ungku Maimunah binti Ungku Abdul Majid.[2][3] He was made the Tunku Mahkota of Johor on 2 November 1895, when Tunku Ibrahim was installed as the Sultan of Johor following Sultan Abu Bakar's death. He spent several years in Perak, where he was enrolled into the Malay College Kuala Kangsar.[4] In March 1912, Tunku Ismail was sent to England to receive his tertiary education in a boarding school; his brothers Tunku Abu Bakar and Tunku Ahmad later followed suit.[5]