The Portaulun were an indigenous Australian people of South Australia. Portaulun language is a dialect of Ngarrindjeri language.
The Portaulun's territory was estimated by Norman Tindale to encompass roughly , along the western bank of the Murray River from Wood Hill to Wellington and Pomanda Point. Their westward extension ran to Grote Hill.
The Portaulun were divided into clans, the name of two of which are known:
The Welindjeri name is a post-colonial, being formed on the introduced toponym of Wellington, and thus meaning 'belonging to the Wel'.
The last Portaulun full-blood was David Unaipon (or David Ngunaiponi), who died in 1967.