Bradley was born in 1938 in Toronto, Ontario, Canada. He was brought up with two older sisters roughly 100 kilometers east of Toronto in the small town of Cobourg, Ontario. His mother raised the children alone after Bradley's father left the family when he was a toddler. Bradley learned to read at an early age, partly because he was a sickly child who spent a lot of time in bed. However, Bradley confesses to having been a "very bad student", particularly in high school, spending his free time reading in the local cemetery because he felt he didn't fit in.
After completing his education, Bradley worked in Cobourg as a radio and television engineer, designing and building electronic systems. He then worked briefly for Ryerson Polytechnical Institute in Toronto (now Ryerson University), before moving to Saskatoon to take a job at the University of Saskatchewan in 1969. There he helped develop a broadcasting studio, where he worked as Director of Television Engineering for 25 years. He took an early retirement from the university in 1994 in order to become a full-time writer.Since selling their home in Kelowna, British Columbia in 2009, Bradley and his wife Shirley have been traveling, hoping to spend time living in various places and visiting every country that is publishing his books.