Aristaenetus was a Greek author who lived during the late antique period, most likely in the 5th or 6th century CE. Beyond his name, no reliable facts about his life or identity are known. He is remembered solely as the writer of a collection of fifty fictional Erotic Letters.

His work belongs to the ancient tradition of epistolography, or letter-writing. The letters are not original stories but are creative reworkings of scenes from earlier Greek literature, including ancient novels, comedies, and the letters of other writers like Alciphron. According to modern scholars, his collection is a clear example of the late antique practice of imitating and repackaging classical themes. The letters have little independent literary value but are significant for understanding how later periods received and recycled earlier Greek texts. They preserve condensed versions of narratives and dialogues from sources that are sometimes fragmentary or lost today, offering insight into the literary tastes and educational practices of his time. The entire collection survives thanks to a single manuscript from the 13th century.