Sultan Haji Ahmad Shah Al-Musta'in Billah Ibni Almarhum Sultan Abu Bakar Riayatuddin Al-Muadzam Shah (24 October 1930 – 22 May 2019) was the fifth Sultan of Pahang from 1974 until his abdication in 2019. He was the seventh Yang di-Pertuan Agong of Malaysia from 26 April 1979 to 25 April 1984. He was born in Pekan, Pahang.