Tuanku Jaafar ibni Almarhum Tuanku Abdul Rahman (born July 19, 1922) in Klang, Selangor was the tenth Yang di-Pertuan Agong (roughly equivalent to King) of Malaysia from April 26, 1994 to April 25, 1999 and fourth Yang di-Pertuan Besar of modern Negeri Sembilan.

The second son of Tuanku Abdul Rahman ibni Almarhum Tuanku Muhammad, he was the first child by his commoner wife, Eurasian nurse Dulcie Campbell. The couple subsequently divorced.

Having studied at the Malay College Kuala Kangsar (MCKK), he graduated from the University of Nottingham before attending Balliol College, Oxford and the LSE. As a second son, Tunku Jaafar joined the civil and diplomatic service of the young Malaysia, but was elected by the Council of Undang to succeed his half-brother Tuanku Munawir in 1967. The election was controversial as the heir presumptive to the throne, Tuanku Munawir's son Tunku Muhriz was by-passed.

Elected Yang di-Pertuan Agong in 1994, he presided over the controversial sacking of Anwar Ibrahim as Deputy Prime Minister by Prime Minister Mahathir Mohamad. Controversially, Tuanku Jaafar was seen to be a silent bystander as Anwar Ibrahim was subsequently detained and severely beaten by the Inspector-General of Police. Public pleas for Tuanku Jaafar to exercise his prerogative authority as Yang di-Pertuan Agong to bring justice for Anwar Ibrahim fell upon deaf ears.

Tuanku Jaafar married his stepmother's younger sister, Tuanku Najihah binti Almarhum Tunku Besar Burhanuddin of Negeri Sembilan, who also served as his Raja Permaisuri Agong.