Knud Plesner Ibsen (3 October 1797 in Skien – 24 October 1877 in Skien) was the father of playwright Henrik Ibsen, and is widely considered the model for many central characters in his son's plays, including most famously Jon Gynt in Peer Gynt and Old Ekdahl in The Wild Duck, but also Daniel Hejre in The League of Youth.