Calca is a small township around 20 kilometres (12 mi) south-east of Streaky Bay, on the southern border of the Calpatanna Waterhole Conservation Park, Eyre Peninsula.
The land was occupied by James Baird (for whom nearby Baird Bay was named), calling it "Kolka" (Aboriginal for 'stars'). Baird, also referred to as Henry Baird, was killed by Aborigines in 1850. A pastoral lease was held by Adam Borthwick from 10 February 1856 (lease no. 554).
The postcode for Calca is 5671.