Ferguson shipbuilders, in Port Glasgow, will build the new vessels for CalMac. Described as the world's first environmentally friendly hybrid ferries, the work will create 100 jobs and secure 745 existing posts.
The contract, which will provide work for the next two years, will also see 20 apprentices taken on.
Infrastructure Secretary Alex Neil announced the deal today.
The Inverclyde yard will work with Glasgow- based ship designers Seatec to produce the two ferries to be use on the Sconser to Raasay route on Skye.
Mr Neil said: "The two new ferries will come into operation in 2013 and are the world's first seagoing passenger and vehicle roll-on roll-off ferries to incorporate a low-carbon hybrid system of diesel electric and battery power.
"The technology will be cleaner, quieter and cheaper to operate and maintain than ever before."
"This project will provide a boost for commercial shipbuilding on the Clyde – it has been over four years since the last commercial ship was fully built and delivered."
Richard Deane, Managing Director of Ferguson Shipbuilders Ltd added: "It is wonderful to be part of such a ground breaking project, which will see the world's first hybrid ferries sailing in Scotland.
"The project will have a major impact on the local economy."
The two ferries will each have space to carry 150 passengers and 23 cars.