MBTA operates a train from Boston to Mendon hourly. Tickets cost $5 - $10 and the journey takes 1 h 4 min.
How to get from Boston to Mendon
From South Station train to Forge Park/495 then taxi to Mendon. 1 h 15 min $36. From Boston taxi to Mendon. 48 min $263. From Boston drive to Mendon. 48 min $5. From Boston, MA - South Station bus to Framingham Flutie Pass, MA then taxi to Mendon. 53 min $95.