His new deal comes a little more than a month after fellow starlet Phil Jones, 18, was rewarded with a new contract with teenage teammate Junior Hoilett's future secured a few months previous.
Steven Nzonzi and Nikola Kalinic can also look forward to long Ewood Park futures after signing on lengthy deals last summer and Olsson predicts good times ahead.
He told the Lancashire Telegraph: "I think there being so many youngsters coming through into the first team together has actually helped us.
"We all get on well and are all inspired by each other.
"None of us want to be left behind and so keep trying to do better and better.
"The club has put their faith in us, we know that, and hopefully we are repaying them. We know we have to keep repaying them though."