He was elected as a member of the House of Assembly of Papua and New Guinea in 1968 and went on to hold several ministerial positions during the period of self-governance and after PNG's independence in 1975, including that of deputy prime minister.

In Port Moresby he was a member of the Bully Beef Club, a political discussion group that included several Sogeri students and led to the founding of the Pangu Pati, which would form PNG's first independent government in 1975.

[1][2][3] Olewale won the South Fly Open seat in the 1968 election for the House of Assembly of Papua and New Guinea.

To a certain extent this was by default as Albert Maori Kiki was expected to become the deputy prime minister, but he failed to be elected.

Together with the secretary for foreign affairs, Anthony Siaguru, Olewale negotiated the Torres Strait Treaty with Australia and a border agreement with Indonesia.

In 1994, on the recommendation of the PNG government, the Commonwealth Secretariat chose him to be an observer at the first post-Apartheid general election in South Africa.

In 2000, he was appointed as a director of the Papua New Guinea Sustainable Development Program Ltd, which worked mainly in Western Province, a position he held until his death.