Aratus (; ; 271–213 BC) was a statesman of the ancient Greek city-state of Sicyon and a leader of the Achaean League. He deposed the Sicyonian tyrant Nicocles in 251 BC. Aratus was an advocate of Greek unity and brought Sicyon into the Achaean League, which he led to its maximum extent. He was elected strategos numerous times and led the Achaeans against Macedonia, the Aetolians and the Spartans. After the Spartans defeated and nearly destroyed the cities of the Achaean League, he requested Antigonus Doson of Macedonia to help fight against the Aetolians and Spartans. After Antigonus died in 222 BC, Aratus did not get along with Philip V of Macedon, who wanted to make the Achaean League subject to Macedonia. Polybius and Plutarch record that Philip had Aratus poisoned.