He was a Country Party/National Party member of the New South Wales Legislative Assembly from 1967 to 1981, representing the electorate of Bathurst.

He entered family furniture business in 1946 and was a reporter on Bathurst's local newspaper, The Western Advocate.

Osborne was endorsed as the Country Party candidate for the seat of Bathurst at the 1965 State election, running against sitting Labor Member, Gus Kelly.

The Labor Member for Blue Mountains, Mick Clough moved seat to contest Bathurst and won with a margin of 0.05%.

[6] Osborne unsuccessfully contested the 1984 election in an unusual move where the National Party (following another name change) endorsed two candidates.