There have been three baronetcies created for descendants of the ancient Norman family of Molyneux who were granted extensive estates in Lancashire after the Norman Conquest.

Earl of Sefton was a title in the Peerage of Ireland created in 1771 for the 8th Viscount Molyneux. The Earls of Sefton held the subsidiary titles Viscount Molyneux, of Maryborough in the Queen's County, in the Peerage of Ireland, and Baron Sefton, of Croxteth in the County Palatine of Lancaster, in the Peerage of the United Kingdom.