Dellandrea was raised in Northern Ontario, Canada. His father Aubrey was a Plymouth Brethren preacher who in the 1960s started the Heavenly Sunshine Broadcast. He attended high school in North Bay, Ontario, where he met his wife, Lyne Edwards. They married shortly before moving to Toronto, where they both attended the University of Toronto. Dellandrea received his BA (English literature) from Scarborough College, both his MEd and EdD from the University of Toronto (Ontario Institute for Studies in Education). (He would later also receive an honorary degree from Oxford University.) The couple moved to Waterloo, Ontario, in 1979 to raise their two sons, Matthew and Brendan, and for Dellandrea to take a position at the University of Waterloo. During this time, Dellandrea took on a central development role, culminating in his appointment to the newly created position of vice-president of university development in 1983.