Trenitalia operates a train from Turin to Monterosso al Mare hourly. Tickets cost $12 - $27 and the journey takes 2 h 9 min. Trenitalia also services this route every 2 hours. Alternatively, FlixBus operates a bus from Turin to Monterosso al Mare 5 times a week. Tickets cost $16 - $28 and the journey takes 4 h 20 min. 2 other operators also service this route.
From Torino Porta Nuova train to Genova Brignole then train to Monterosso. 4 h 18 min 28€. From Turin, Torino bus to La Spezia - Instituto Cardarelli, bus to La Spezia Centrale, then train to Monterosso. 5 h 33 min 27€. From Turin drive to Monterosso al Mare. 2 h 56 min 39€.