Permaisuri Siti Aishah (Jawi: ڤرمايسوري سيتي عائشه; born Siti Aishah binti Abdul Rahman; born 18 November 1971) is the consort of the 11th Yang di-Pertuan Agong of Malaysia, Sultan Salahuddin Abdul Aziz Shah. She is the youngest ever Raja Permaisuri Agong (Queen) of Malaysia, ascending the throne at the age of 28 on 26 April 1999. During her reign as Raja Permaisuri Agong, she was known as Tuanku Siti Aishah.