David Ernest Oldfield (b. 1958) is a Member of Parliament in the State of New South Wales, Australia. He grew up in Manly, a beachside suburb of Sydney, the largest city in Australia. In the 1990s Oldfield was prominent in municipal politics, representing the Liberal Party on Manly Municipal Council.

While working as a senior staffer for Tony Abbott in 1996, a prominent Liberal Party Member of Australia's national Parliament, Oldfield secretly founded the One Nation Party in concert with Pauline Hanson and David Ettridge.

David Oldfield easily won a seat in the Legislative Council (Upper House) of the New South Wales Parliament in the New South Wales state elections of March 1999. However, he was expelled from the One Nation Party by Pauline Hanson in 2000 and founded a separate party of which Oldfield is the President, the One Nation NSW Political Party.