The offer, which began Monday, is for any student with a valid student ID.
Students can get the offer by downloading the Metrolink mobile app, registering with a school email address and verifying their account.
Students will then receive a "Student Adventure Pass" in their mobile ticket wallet. You can also get the Student Adventure Pass at a Metrolink ticket machine.
The free rides are courtesy of the Low Carbon Transit Operations Program administered by Caltrans.