Morrison, part of Galliford Try, is building a new campus for Cumbernauld Academy, which was formed following the merger of Cumbernauld and Abronhill high schools in August 2014.
The school currently has around 980 pupils but the new campus on South Kildrum Ring Road will have capacity for 1250 pupils as well as a 300-seat replacement venue for the current Cumbernauld Theatre.
Once the construction work is completed then the current school building will be demolished to make way for new outside sports facilities.
To mark the start of works, deputy first minister John Swinney visited the site for a turf cutting ceremony.
The £37m Cumbernauld Academy project is the third in a series of collaborations between Morrison Construction, North Lanarkshire Council and Hub South West Scotland, following on from the construction of the new £31.2m premises for Greenfaulds High School in Cumbernauld and the £26m Clyde Valley Campus over the past couple of years.