Announcing the decision, housing minister Kevin Stewart said it had been used in more than 12,000 purchases since its launch in 2013 and also supported around 9,000 jobs in the country.
A sizeable chunk, around £18m of the £50m annual budget, will be set aside to be used on purchases from SME housebuilders, the Scottish government added.
The move was welcomed by trade body UK Finance Scotland Mortgage Committee chairman Douglas Cochrane.
“The extension of Help to Buy in Scotland is good news for buyers and home movers with low deposits, who will continue to receive vital support when buying a new-build home,” he said.
“Last year the number of first-time buyers in Scotland reached its highest level in a decade, boosted by vital schemes like Help to Buy.
“Today’s announcement will bring welcome stability to the Scottish mortgage market and help more people get a foot on the housing ladder in the years ahead.”