Wallis was born at Thornleigh in New South Wales and served in World War II from 1939 to 1941.

A boilermaker by trade, he moved to South Australia to work for the Commonwealth Railways at Port Augusta in 1943.

[1][2][3] He was elected to the House of Representatives at the 1969 federal election, defeating one-term Liberal MP Don Jessop in the seat of Grey, then a marginal seat centred on industrial towns in western South Australia.

He was re-elected five times, with the 1977 election - at which his seat doubled in geographic size - being his closest race, won by only 65 votes after three recounts.

[1][2][3][4][5] Wallis died, aged 61, of lung cancer on 10 January 1984 in Port Augusta, South Australia.