Lycus of Rhegium was a Greek historian from the city of Rhegium in southern Italy, active during the 4th–3rd centuries BCE. As a native of this culturally mixed city in Magna Graecia, he was positioned at a significant crossroads during the Hellenistic period. No details of his personal life or education survive.

Two lost historical works are attributed to him, preserved only in fragments cited by later authors: On Sicily, a history of Sicily, and On Libya, concerning the history and geography of North Africa. Lycus is significant as a source for later historians and geographers. His works were used by authors such as Agatharchides of Cnidus, Antigonus of Carystus, and Strabo, who cites him on Sicilian and Libyan geography.

His writings represent the local historiography of Magna Graecia and contribute to our understanding of how peripheral Greek historians documented their own and neighboring regions.