Buller District Mayor Jamie Cleine said the council had reached an agreement with Nelson-based Originair, which would start services from January 3.
Flights on the 18-seater, twin-turboprop plane will run six days a week, with morning flights leaving Westport Monday to Thursday, and afternoon flights on Fridays and Saturdays for leisure travellers.
The airline already flies between Nelson and Palmerston North, Hamilton and Wellington.
Originair chief executive Robert Inglis said it was looking forward to developing business and leisure travel to the West Coast.
"The initial flight schedule reflects current passenger demand, but we are prepared to increase services ... as the region’s needs evolve."
The route was previously served by Sounds Air.
Sounds Air managing director Andrew Crawford said the decision to suspend its Wellington/Westport services was "a regrettable outcome driven by the same challenges that continue to impact on Air New Zealand’s own domestic and international services".
Air New Zealand withdrew from the route in 2016.
