Archidamus II was a king of Sparta who reigned from approximately 469/8 BC to 427/6 BC. His father was Zeuxidamus (called Cyniscos by many Spartans). Zeuxidamus married and had a son, Archidamus. However, Zeuxidamus died before his father, Leotychidas.
After the death of his son and heir, Leotychidas married Eurydame, the sister of Menius and daughter of Diactorides. While they had no male offspring, they did have a daughter, Lampito, whom Leotychidas gave in marriage to his grandson Archidamus. They had a son Agis II.
Archidamus' later second marriage was to Eupolia. The Ephors objected to this union, arguing that due to Eupolia's short stature, “She will bear us kinglets instead of kings”. He married her nonetheless and was for that fined by the Ephors.
To them were born a son, Agesilaus II, and a daughter, Cynisca.