The knowledge, attitudes, and beliefs of key policy influencers and the general public can support or hinder the development of public policies that support cancer prevention. To address gaps in knowledge concerning healthy public policy development, views on cancer causation and endorsement of policy alternatives for cancer prevention among government influencers (elected members of legislative assemblies and senior ministry bureaucrats), non-governmental influencers (school board chairs and superintendents, print media editors and reporters, and workplace presidents and senior human resource managers), and the general public were compared. Two structured surveys, one administered to a convenience sample of policy influencers (government and non-governmental) and the other to a randomly selected sample of the general public, were used. The aim of these surveys was to understand knowledge, attitudes, and beliefs regarding health promotion principles and the priority and acceptability of policy actions to prevent four behavioral risk factors for cancer (tobacco use, alcohol misuse, unhealthy eating, and physical inactivity). Surveys were administered in Alberta and Manitoba, two comparable Canadian provinces. Although all groups demonstrated higher levels of support for individualistic policies (e.g., health education campaigns) than for fiscal and legislative measures, the general public expressed consistently greater support than policy influencers for using evidence-based policies (e.g., tax incentives or subsidies for healthy behaviors). These results suggest that Canadian policy influencers may be less open that the general public to adopt healthy public policies for cancer prevention, with potential detriment to cancer rates.