Roger de Mortimer (died before 8 July 1214) was a medieval marcher lord, residing at Wigmore Castle in the English county of Herefordshire. He was the son of Hugh de Mortimer (d. 26 February 1181 and Matilda Le Meschin. He was born before 1153.Roger would appear to have been of age in 1174 when he fought for King Henry II against the rebellion of his son, Henry. In 1179 Roger was instrumental in the killing of Cadwallon ap Madog, the prince of Maelienydd and Elfael, both of which Mortimer coveted. He was imprisoned until June 1182 at Winchester for this killing.He is often wrongly stated to have been the father of Robert Mortimer of Richards Castle (died 1219) - married Margary de Say, daughter of Hugh de Say. This Robert was born before 1155 and therefore could not have been a son of Roger.