The national renewables infrastructure fund will be available immediately and runs until 2015. It is predicted to create 28,000 jobs.
"The offshore wind industry is seeking leadership and immediate support and the government is determined to provide that," said first minister Alex Salmond. "We want to stimulate the market and act decisively to trigger vital investment and launch the next phase of Scotland's renewables revolution."
Industry body Scottish Renewables said the fund could make the difference between landing major inward investment and missing out to other parts of the UK and Europe. Friends of the Earth Scotland also welcomed the announcement.
Sites at Leith, Dundee, Nigg, Methil, Hunterston, Aberdeen, Arnish, Ardersier, Campbeltown, Kishorn and Peterhead have already been identified as potential turbine manufacturing sites.