Longus (Greek: Λόγγος) was a second-century Greek novelist. His work, Daphnis and Chloe, can be considered one of the first novels in the history of literature, which makes it an essential classic.

Nothing is known of his life. He is believed to have lived on the island of Lesbos in Hadrian's time. There is also nothing certain about his name. It is, yes, a Greek writer of Roman times and possibly was a freedman of a family with the surname Longo.