From 1945 to 1947 he served in the Royal Australian Navy as a sub-lieutenant aboard HMAS Hawkesbury before returning to manage cattle properties in Barmundu and Kingaroy.
[1] Harper was a member of the National Party, and served as chairman of the Wandoan branch.
Promoted to the front bench as Attorney-General and Minister for Justice in 1983, moving to Primary Industries in 1986 and to Land Management in 1989.
Following the Nationals' defeat in 1989 he became Shadow Attorney-General, but his seat of Auburn was abolished in 1992 and he was defeated for preselection in Callide by sitting member Di McCauley, choosing subsequently to retire.
[1] Neville Harper died in Alexandra Headland, Queensland on 29 September 2023, at the age of 97.