Archidamus IV (Greek: Ἀρχίδαμος Δ΄) was Eurypontid king of Sparta from c. 300 BC to c. 275 BC. An obscure king, Archidamus is only known for his defeat against the Macedonian king Demetrius Poliorketes at Mantinea in 294, where he might have also died since nothing is heard of him afterwards. This defeat marks the beginning of a long eclipse for the Eurypontid kings, who are not mentioned again until the emergence of Agis IV 50 years later.