John of Brittany (; c. 1266 – 17 January 1334), 4th Earl of Richmond, was an English nobleman and a member of the Ducal house of Brittany, the House of Dreux. He entered royal service in England under his uncle Edward I, and also served Edward II. On 15 October 1306 he received his father's title of Earl of Richmond. He was named Guardian of Scotland in the midst of England's conflicts with Scotland and in 1311 Lord Ordainer during the baronial rebellion against Edward II.