Jean Chacornac (June 21, 1823 – September 23, 1873) was a French astronomer.
He was born in Lyon and died in St Jean en Royans. Working in Marseille and Paris, he discovered six asteroids and the comet Chacornac C/1852 K1 which may be the source of the current Eta Eridanids meteors. The asteroid 1622 Chacornac and the crater Chacornac on the Moon are named in his honour.