St. Ann's Head Lighthouse is a lighthouse that overlooks the entrance to the Milford Haven Waterway, one of Britain's deep water harbours, from St. Ann's Head near Dale in Pembrokeshire.

The lighthouse is intended to guide ships around a number of rocky shoals that cause a hazard to shipping entering the Haven as well as Crow's rock.

The current lighthouse was completed in 1844, at which time it was known as St. Ann's Low Light, and was commissioned by John Knott, senior lighthouse keeper with Trinity House.

The present operational tower is 13 metres (43 ft) in height and is painted white.

Visible is Skokholm Lighthouse on the small island of Skokholm 8 kilometres (5.0 mi) to the west.