While theories of physical activity (PA) behaviour change are taught to undergraduate students in a range of programs, there is little guidance on which theories should be taught prior to graduation. Aim: To determine which PA behaviour change theories are recommended to be taught to undergraduate students in PA and/or exercise science by the time they graduate. Methods: A Delphi consensus exercise was completed by instructors from across Canada who taught PA behaviour change to undergraduate students. In Round 1, 18 professors completed an online questionnaire to generate a list of PA theories taught. In Round 2, 15 instructors indicated their level of agreement using an 11-point Likert scale as to whether the theories from Round 1 should be taught. In Round 3, 12 instructors were presented a refined list of theories that received high consensus in Round 2 (Mean Score: >7 and rated >7.0 by >66% of participants) and indicated their level of agreement. Results: Round 1 identified 39 theories. After Round 2, 9 theories met consensus guidelines which was further refined to 5 theories in Round 3. However, interclass correlations statistics revealed little consistency in theory ratings. Conclusions: A wide range of theories are taught to undergraduate students and there is a lack of consensus among experts as to which theories should be taught to students. Findings will inform the instruction of behavior change theories in PA and/or exercise science at an undergraduate level.