Sir Marcus Somerville, 4th Baronet (1772 – 11 July 1831) was an Anglo-Irish politician.

Somerville was the son of Sir James Quaile Somerville, 3rd Baronet and Catherine Crofton. He was the Member of Parliament for Meath in the Irish House of Commons in 1800, before sitting for its successor constituency in the House of Commons of the United Kingdom until his death in 1831. He was a Whig.

In 1800, Somerville succeeded to his father's baronetcy. He married Mary Anne Meredyth, daughter of Richard Gorges-Meredyth, on 11 August 1801 and they had two sons, the eldest being William Somerville.