Which Greek author wrote the Labours of Hercules in Greek mythology?

You know, I don’t know. Luckily, Wikipedia does: Labours of Hercules.

Some ancients tells us that Peisander of Camirus wrote the official account of the labours as an epic. Some other ancients (via Clement of Alexandria) tells us that Peisander got his material from some other guy called Pisinus of Lindus.

Neither of these particularly matter to you, because neither guy’s work has been preserved. The writeup we do have of the labours is the Bibliotheca of Pseudo-Apollodorus, a first/second century AD compendium, which is our go-to source for a lot of the fine print of Greek mythology.