Construction starts this week on three of the four projects. These are a new grammar school at Kirkwall including an arts theatre, a new primary school in Stromness and a new swimming pool and squash courts at the Pickaquoy Centre along with three all weather pitches.
A hall of residence at Papdale will start next year.
As part of the contract Galliford Try Facilities Management will provide a range of services for 10 years including building and grounds maintenance.
The project which is being funded with support from the Scottish Government and advice from the Scottish Futures Trust, will see work across four main facilities.