A theory for the name of the area is that it was taken from Seaforth House, named after Francis Mackenzie, 1st Baron Seaforth, who built the mansion in 1813 for his daughter and her husband, Sir John Gladstone, father of William Ewart Gladstone, four times British Prime Minister.

A permanent military presence was established in the borough with the completion of Seaforth Barracks in 1882.

Seaforth became part of Crosby Municipal Borough in 1937, having previously been part of Waterloo with Seaforth Urban District. The area then became part of the new Borough of Sefton on 1 April 1974.

Seaforth is well served by road (A565 and) and rail; its one station is 'Seaforth and Litherland'.

Seaforth Dock opened in 1972 and is the largest dock facility on Merseyside. It is part of the Port of Liverpool and Liverpool Freeport.