TrainOSE S.A. (, pronounced trenosé) is a railway company in Greece which currently operates all passenger and freight trains on OSE lines. The company, formerly a subsidiary of the Hellenic Railways Organisation (OSE), has been from 2008 an independent state-owned company. TrainOSE employs all train crews, operators and manages the rail services throughout the Greek railway network, but does not own any rolling stock, leasing rolling stock owned by OSE instead.

TrainOSE S.A. (, pronounced trenosé) is a railway company in Greece which currently operates all passenger and freight trains on OSE lines. The company, formerly a subsidiary of the Hellenic Railways Organisation (OSE), has been from 2008 an independent state-owned company. TrainOSE employs all train crews, operators and manages the rail services throughout the Greek railway network, but does not own any rolling stock, leasing rolling stock owned by OSE instead.