Tophill is a gently sloping area of land on the Isle of Portland in Dorset, England. Rising from sea level at Portland Bill to 151 metres (495 ft) near HMP The Verne at its northern end, Tophill contains the villages of Easton, Weston, Southwell, the Grove and Wakeham. The lower northern end of the island is called Underhill.
In the north-west corner of Tophill is Tout Quarry, whilst the nature reserve King Barrow Quarry lies at the north-east.
In the New Ground area, in front of the Portland Heights Hotel, sits the Portland Cenotaph.