The Tasmanian Government will invest $800,000 upgrading a key road on King Island.

The Infrastructure Minister, David O'Byrne, said the work on Pegarah Secondary Road will boost jobs and the local economy.

The 11.8 kilometre road covers about half the distance between Naracoopa and Currie, via Pegarah.

"We know it's a particularly difficult and uncertain time for King Islanders, and the State Government is focussed on helping in any way we can," Mr O'Byrne said.

"The upgrade will seal 3.6 kilometres of gravel road, and provide jobs for local workers.

"It's a win for jobs, road safety, and efficiency for local industry.

"The Memorandum of Understanding between the State Government and King Island Council on island roads is working well, and this is an important project at a crucial time," he said.

The King Island Council will conduct the work under a Deed of Agreement with the State Government.

"This upgrade is a good example of state and local governments working together to support jobs and local investment," Mr O'Byrne said.

"We'll continue working closely through the Government Partnership Agreement to unlock economic opportunities and strengthen the community," he said.

The King Island Mayor, Greg Barrett, welcomed the upgrade.

"Sealing Pegarah Road is a major priority for us. It effectively transforms travel safety and efficiency to the eastern side of the island," Councillor Barrett said.

"Many people and groups have worked for more than a decade to achieve this. It's very exciting and timely given the current situation on the island. 

"Credit must go to our current general manager, Mark Goode, for pursuing this project with passion and commitment," he said.