Blackmore will be responsible for increasing Galliford Try’s market share in existing sectors and progressing aligned adjacent market opportunities.
He takes over from David Lowery who was promoted to the board role of divisional managing director of Environment and Infrastructure three months ago.
Glennan brings more than 30 years’ experience in construction, with 18 years spent at Skanska where he most recently was highways director.
Lowery said: “Infrastructure remains a key focus for our organisation, and we are excited that Glennan, with his wealth of experience, has joined our business for the next and important phase of our journey.”