Timothy John Whetstone is an Australian politician representing the seat of Chaffey in the South Australian House of Assembly for the South Australian Division of the Liberal Party of Australia since the 2010 election. Whetstone served as the Minister for Primary Industries and Regional Development in the Marshall Ministry from 22 March 2018. He resigned from cabinet on 26 July 2020 after a scandal over parliamentary allowances.

The 2010 South Australian state election elected members to the 52nd Parliament of South Australia on 20 March 2010. All seats in the House of Assembly or lower house, whose current members were elected at the 2006 election, and half the seats in the Legislative Council or upper house, last filled at the 2002 election, became vacant.