Fontmell Magna is a village and civil parish in Dorset, England. It is situated in the Blackmore Vale, close to the chalk hills of Cranborne Chase, on the A350 road five miles south of Shaftesbury and eight miles north of Blandford Forum. In the 2011 census the parish had a population of 734.

The A350 is a north–south primary route in southern England, that runs from the M4 motorway in Wiltshire to Poole in Dorset.