Lieutenant-Colonel Thomas Howard, 3rd Earl of Effingham PC (13. January 1746 – 19 November 1791), styled Lord Howard until 1763, was a British nobleman and Army officer, the son of Thomas Howard, 2nd Earl of Effingham. He is best known for resigning his commission in protest against the war against the American colonies. This widely-reported act was commemorated by the American colonists in the naming of a galley in 1775, and later the frigate USS Effingham in 1777 - as well as in the naming of Effingham, New Hampshire, Effingham County, Georgia and Effingham County, Illinois.