Coiny is a French surname. Notable people with the surname include:
People Jacques Joseph Coiny (1761–1809), French engraver Joseph Coiny (1795–1829), French engraver, son of Jacques Joseph Coiny
Fictional characters Coiny, a character from the first season of Battle for Dream Island, an animated web series Coiny, the mascot for PayPal Honey, a money saving website online