Boston Express operates a bus from Boston to Peterborough every 3 hours. Tickets cost $15 - $18 and the journey takes 1 h 5 min. Amtrak also services this route every 4 hours. Alternatively, MBTA operates a train from Boston to Peterborough hourly. Tickets cost $7 - $12 and the journey takes 1 h 26 min.
From Boston, MA - South Station bus to Nashus, NH then taxi to Peterborough. 1 h 44 min $218. From North Station train to Fitchburg then taxi to Peterborough. 2 h 7 min $211. From Boston drive to Peterborough. 1 h 34 min $8.