Norway-based Marine Harvest already run 38 farms in Scotland, supporting about 460 jobs.
Chairman Ole-Eirik Leroy said: "With people eating more salmon and the need to sustainably increase our production, we believe that further investment in Scotland is good for our business and the Scottish economy, the communities where we operate and our consumers.
"Because of this we are looking at investment plans for Scotland in the region of £80million between 2012 and 2016 that could create around 100 jobs."
Marine Harvest recently opened two new sites in the Western Isles on Barra and South Uist, employing 11 staff in total. Work on a new £15million re-circulation hatchery at Lochailort began just recently with the opening planned for spring next year.
First Minister Alex Salmond met Mr Leroy during a visit to Oslo, the capital of Norway, where they discussed the firm's five-year investment plan.
Salmond said he is determined to support the industry, which employs more than 2100 people in Scotland directly.
He added: "Scottish salmon now accounts for more than a third of the value of our national food exports, reflecting the premium that discerning consumers place on Scottish salmon, including in expanding markets such as China, where we were able to secure agreement with the government in Beijing to enable direct exports to the country last year.
"Fresh farmed salmon sales in the Far East soared nearly 900 per cent last year to a record 6779 tonnes, demonstrating the growing demand for Scottish seafood from new marketplaces.
"I was pleased to hear first hand about Marine Harvest's plans for their operations in Scotland and delighted by their latest investment commitment that will benefit local communities.
"Clearly they are set to play a key role in our ambitions for growth in the industry, including our aim of increasing production by 50 per cent on 2009 levels to 210,000 tonnes by 2020."
Anne MacColl, chief executive of Scottish Development International, said: "The decision by Marine Harvest to commit to a five-year investment plan in Scottish rural communities is testament to the international reputation Scotland currently has in the sustainable salmon farming industry."