In 1971 Dennis Mock joined Ryerson faculty in Social Sciences Department as a geography professor. He was part of a group who created the first Applied Geography program in Canada, offered for first time in 1975 at Ryerson. Between 1979 and 1987 he was the chair of the Geography Department. In 1987 he was awarded the Distinguished Service Award of the Canadian Association of Geographers for the work he did on a committee that restructured the Ontario high school geography curriculum. In 1988 he was a visiting professor of geography for six weeks in Australia. On May 1, 1989 he was appointed Ryerson's Registrar. Up to this point Dennis Mock had participated in many committees and activities including Chair of the Academic space Planning Committee; Represented Ryerson on the Council of Ontario Universities OSIS liaison committee; Chair of Academic Term Committee of Academic Council; Chair of the GPA Committee; Member of Academic Council (now the Senate); Arbitrator to resolve faculty appeals (at least 3 occasions); Appeals Committee of the Ryerson Faculty Association; and Chair of the Arts Re-organization Committee. In 1989 he was appointed the Vice President Academic, a post he held for 11 years. Between August 1990 - Jan 1991 he was Acting President. In 2000 Dennis Mock retired from Ryerson and the University established the Dennis Mock Student Leadership Awards in honour of his years of service to the University.