It is a rural parish surrounding the town of Calne, extending west to the Avon and south to the Roman road from London to Bath.

Settlements in the parish are the village of Derry Hill; the small villages of Calstone Wellington, Sandy Lane, Stockley and Studley; the dispersed settlement of Stock; the hamlets of Blackland, Broad's Green, Buck Hill, Mile Elm, Pewsham and Theobald's Green; and part of the hamlet of Ratford.

The parish also encompasses the former tithing of Calstone, and the country house estates of Bowood and Whetham.

[2][4] Finally, when Pewsham parish (to the west) was abolished in 1984 its rural area was transferred to Calne Without.

[5] The River Marden flows through the parish from its source near Calstone Wellington.