Sultan Salahuddin Abdul Aziz Shah Al-Haj ibni Almarhum Sultan Hisamuddin Alam Shah Al-Haj (Jawi: سلطان صلاح الدين عبدالعزيز شاه الحاج إبن المرحوم سلطان حسام الدين عالم شاه الحاج; 8 March 1926 – 21 November 2001) was the Sultan of Selangor from 1960, and the eleventh Yang di-Pertuan Agong (King of Malaysia) from 1999, until his death in 2001.

The Kota Darul Ehsan arch was erected along the Federal Highway at the border of Kuala Lumpur and Selangor to commemorate the event in 1981.

Sultan Salahuddin was elected as the eleventh Yang di-Pertuan Agong on 26 April 1999 and installed on 11 September 1999.

He died in office on 21 November 2001, at the Gleneagles Intan Medical Centre in Kuala Lumpur after reigning for two years and 6 months.

He underwent a heart operation to put a pacemaker two months prior to his death, which he did not fully recover from.

His first wife and cousin, Paduka Bonda Raja Raja Nur Saidatul Ihsan binti Al Marhum Raja Bendahara Tengku Badar Shah, whom he later divorced, bore: Che Maheram binti Muhammad Rais, his second wife, bore him: His royal consort, Tengku Ampuan Rahimah binti Sultan Abdul Aziz Shah of the Langkat royal family in Sumatra died in 1993 before his election as Yang di-Pertuan Agong.

She was the mother of: His last wife, Tuanku Siti Aishah binti Abdul Rahman, who was a commoner, served as his Raja Permaisuri Agong.

The Sultan also loved sailing, collecting antique cars, rearing animals and planting orchids.