| Succession: | King of Cyrenaica |
| Reign: | 600-583 BC |
| Predecessor: | Battus I |
| Successor: | Battus II |
| Death Date: | 583 BC |
| Death Place: | Cyrene |
| Issue: | Battus II Critola |
| House: | Battiadae |
| Father: | Battus I |
| Religion: | Greek polytheism |
Arcesilaus I of Cyrene (Greek, Modern (1453-);: Ἀρκεσίλαος; died 583 BC), also spelled Arkesilaos I, was the second Greek king of Cyrenaica and the second king of the Battiad dynasty.
Arcesilaus was the son of Battus I, the first king of Cyrenaica and Cyrene. Arcesilaus’ paternal grandparents were the Cretan Princess Phronima and the distinguished Therean nobleman called Polymnestus.
Very little is known on the life and reign of Arcesilaus. He succeeded to the throne after the death of his father in 600 BC. Herodotus says that the number of people in Cyrene during his reign remained equal to the original number of settlers under Battus. Arcesilaus died in 583 BC and was buried near his father.
His son, Battus II, succeeded him. Arcesilaus also had a daughter called Critola.