Wheeldon was appointed Minister for Repatriation and Compensation in June 1974 in Gough Whitlam's third ministry and was responsible for implementing Whitlam's ambitious plan to establish a national compensation scheme. In addition, he was appointed Minister for Social Security in June 1975 when Bill Hayden was appointed Treasurer. Both appointments were terminated by the dismissal of the Whitlam government in November 1975. Wheeldon remained a senator until 30 June 1981, having chosen not to contest the 1980 election.