Professor Osborne holds an LL.B. (Hons.)(Auckland) 1970, and an LL.M. (McGill) 1973. He joined the Faculty of Law in 1971 and was appointed professor of law in 1978. He was visiting professor at the University of Auckland in 1974, 1978, 1984-85, and 1991-92.

Professor Osborne teaches courses in Torts, Insurance Law, Contracts, Agency, Comparative Law, Company Law, and Problems in Contract and Tort.