Unaipon began his education at the age of seven at the Point McLeay Mission School and soon became known for his intelligence, with the former secretary of the Aborigines' Friends' Association stating in 1887: "I only wish the majority of white boys were as bright, intelligent, well-instructed and well-mannered, as the little fellow I am now taking charge of.

He was later employed by the Aborigines' Friends' Association as a deputationer, in which role he travelled and preached widely in seeking support for the Point McLeay Mission.

Muecke and Shoemaker say that between "1910 and 1944 he made ten ... applications for inventions as varied as an anti-gravitational device, a multi-radial wheel and a sheep-shearing handpiece".

He was also known as the Australian Leonardo da Vinci for his mechanical ideas, which included pre World War I drawings for a helicopter design based on the principle of the boomerang and his research into the polarisation of light; he also spent much of his life attempting to achieve perpetual motion.

[13] His employment with the Aborigines' Friends' Association collecting subscription money allowed him to travel widely.

Five of Unaipon's traditional stories were published in 1929 as Native Legends, under his own name and with his picture on the cover.

[9] They have been republished in their original form, under the author's name, as Legendary Tales of the Australian Aborigines.

[20][21] On 4 January 1902 he married Katherine Carter (née Sumner), a Tangane woman who died in 1928, but theirs was not a happy marriage.

[2] Unaipon was inquisitively religious, believing in an equivalence of traditional Aboriginal and Christian spirituality.

[22] Unaipon died in the Tailem Bend Hospital on 7 February 1967 and was buried in the Raukkan (formerly Point McLeay) Mission Cemetery.

Campbell's argument was that the woman (who had since died) originally consulted by the Reserve Bank was not related to Unaipon.

[25][26] Campbell, who said that there was no evidence that the woman from whom permission was obtained in 1994, Melva Linda Carter, was in fact Unaipon's great-niece,[27][28] as she claimed.