Eudoxus of Cyzicus (fl. c. 130 BCE) (Greek: Ευδοχος) was a Greek navigator who explored the Arabian Sea for Pharaoh Ptolemy VIII of Egypt.

Eudoxus made a successful voyage to India and returned with a cargo of perfumes and gemstones, which were immediately confiscated by Ptolemy on his return. Eight years later, after Ptolemy's death, Eudoxus made the same trip again, hoping to make a profit this time, but suffered the same fate from the new Pharaoh, Ptolemy IX.

At some stage during his explorations of the Arabian Sea, Eudoxus had been blown off-course and encountered the East Coast of Africa. This led him to believe that the continent could be circumnavigated. He set out to prove his theory, sailing West from Egypt, but only reached as far as Cadiz in what is now Morocco. On his second attempt, he reached the West coast of Africa, but was never heard from again as he began his journey South.