By 1990, Oldfield was a member of the Liberal Party. He was elected an Alderman of the Manly Municipal Council in September 1991, and while his activity while on the Council remains largely unpublished and unknown, he was a known member of the Environmental Works Community Audit Committee (1993—1995) and the Fisher Road Special School Committee (1994—1996). When Pauline Hanson's One Nation was founded, Oldfield became the first representative of the party on a Local government level. He remained an Alderman of the Council until 1998 when he resigned to stand for the Australian Senate.
