Conan IV (1138 – February 20, 1171) was duke of Brittany, from 1156 to his death. He was son of Alan the Black, Earl of Richmond and Bertha of Brittany. Through his mother he was the nephew and heir of Duke Hoel III. From his father’s side, Conan was great grandson of duke Geoffrey I and grandson of Eudes of Brittany.

Conan had to face several revolts from his own nobles. To sustain the unrest, the duke appealed to the help of king Henry II of England, who, in return, demanded the engagement of Conan’s only daughter and heiress Constance with his son Geoffrey Plantagenet.

See also: Dukes of Brittany family tree