To achieve food security in Canada, comprehensive approaches are required, which involve action at the public policy level. This qualitative study explored the experiences of 14 stakeholders engaging in a 9-month participatory public policy advocacy project to promote community food security in the province of Alberta through the initiation of a campaign to develop a Universal School Food Strategy. Through this exploration, four main themes were identified; a positive and open space to contribute ideas, diversity and common ground, confidence and capacity, and uncertainty. Findings from this study suggest that the participatory advocacy project provided a positive and open space for stakeholders to contribute ideas, through which the group was able to narrow its focus and establish a goal for advocacy. The project also seems to have contributed to the group’s confidence and capacity to engage in advocacy by creating a space for learning and knowledge sharing, though stakeholders expressed uncertainty regarding some aspects of the project. Findings from this study support the use of participatory approaches as a strategy for facilitating engagement in public policy advocacy and provide insight into one group’s advocacy experience, which may help to inform community-based researchers and advocates in the development of advocacy initiatives to promote community food security elsewhere.