It is the latest contract awarded by the council after John Graham and Robertson won two schools worth a combined £22m in February.
Kier will now deliver the third and final project in the Council’s programme of new primary schools for the Fort William area.
Work involves the demolition of the existing Caol Primary School and Caol Community Centre buildings and the construction of two new buildings.
Councillor Alasdair Christie, Chairman of The Highland Council’s Education Children and Adult Committee said: “This is another major investment in the Fort William area as we strive to provide our communities with a learning environment fit for the 21st century.
“We look forward to working with Kier and the successful delivery of this important project at Caol.”
John Graham is building a new school at Lundavra Road to replace the existing Fort William and Upper Achintore Primary Schools while a new Gaelic Medium primary school with community facilities at Ardgour Road in Caol has gone to Robertson Construction Northern Ltd.