Penwortham is a small town in the Clare Valley, South Australia, along the Horrocks Highway, approximately 10 kilometres south of Clare and 14 kilometres north of Auburn.

The Clare Valley is a valley located in South Australia about 100 kilometres north of Adelaide in the Clare and Gilbert Valleys council area. It is the river valley formed by the Hutt River but is also strongly associated with the roughly parallel Hill River. The valley is traversed by the Horrocks Highway and the towns in the valley along that route from south to north are Auburn, Leasingham, Watervale, Penwortham, Sevenhill and Clare. The geographical feature has given rise to the Clare Valley wine region designation, a notable winegrowing region of Australia.