Eudemus of Rhodes was a Greek philosopher of the fourth century BCE. He was a direct student of Aristotle and a prominent member of the Peripatetic school at the Lyceum in Athens. Ancient sources suggest he was considered a potential successor to Aristotle, but after the philosopher's death, Eudemus returned to his native island of Rhodes, where he is said to have founded his own school.

None of Eudemus's own writings survive intact; they are known only through fragments and references by later authors. He produced works closely aligned with Aristotle's projects, including versions or commentaries on Aristotle's Physics and Ethics. One of Aristotle's major ethical treatises is even named the Eudemian Ethics after him, though the exact nature of his connection to the text is unclear. According to modern scholars, he may have been its editor, dedicatee, or the author of a similar version. Eudemus also wrote pioneering histories of geometry, arithmetic, and astronomy. These lost works are considered among the earliest attempts to document the history of scientific thought.

Eudemus's primary significance lies in his role in preserving and transmitting Aristotle's ideas in the early Peripatetic tradition. Furthermore, his historical studies of science established him as an important, though fragmentary, source for the early development of mathematics and astronomy.