Hellenic Train S.A., formerly TrainOSE S.A., is a private railway company in Greece which operates passenger and freight trains on OSE lines. Hellenic Train employs train crews, operators and manages most of the rail services throughout the Greek railway network, leasing rolling stock owned by GAIAOSE except for ETR 470 trains.

The Hellenic Railways Organisation or OSE is the Greek national railway company which owns, maintains and operates all railway infrastructure in Greece with the exception of Athens' rapid transit lines. Train services on these lines are run by Hellenic Train S.A., a former OSE subsidiary, Rail Cargo Logistics Goldair, Pearl and Grup Feroviar Român.