1968, Edper offered Cockwell a job, which Cockwell accepted while he was in South Africa for the Christmas holidays.
Cockwell has been married four times. In 1966 he married his first wife, who had come with him from South Africa to Canada. The marriage ended in divorce. He married secondly to Norma Gail Harding, a Montreal native who was Paul Lowenstein's secretary at Edper. They divorced in the mid 1980s. During his divorce from Norma, Cockwell began dating Wendy Marion Cecil, who was a vice-president at Edper. In August 1986 they had a daughter together, then married in 1987, and later had two sons. Both of Cockwell's sons, Malcolm and Gareth, work in the forestry industry. Cockwell and Cecil divorced in 2000. From 2010 to 2017, Cecil served as chancellor of Victoria University. In 2001, Cockwell married Lynda Hamilton, the third wife and widow of Peter Bronfman.