In 1974, Minister of Health and Welfare, Marc Lalonde introduced the report, A New Perspective on the Health of Canadians. The â€œLalonde Report,â€ as it came to be known, ushered in a new era of public health and health promotion internationally, by expanding the view of health from the biomedical understanding that existed at the time. Specifically, the report drew attention to influences on health outside of the health care system (e.g., environment, lifestyle). Little is known, however, about the history of the â€œsocial determinants of healthâ€ (SDOH) concept in Canada prior to the introduction of the Lalonde Report. There is much to be learned from the Canadian Public Health Association's (CPHA) longstanding history (est. 1910) as a non-governmental organization committed to improving the health of Canadians. For example, CPHA's longstanding concern with improving the living conditions of Canadians through action on determinants of health such as housing, poverty, and employment, suggest that the history of the SDOH concept extends far beyond 1974. This study reports findings from CPHA's archives (e.g., meeting minutes, resolutions, reports, newsletters) and oral history interviews conducted with individuals pertinent to the uptake of the SDOH concept. This study presents unheard histories of the SDOH, its key figures, events, and circumstances. Lessons learned from history will provide insight into the contemporary issues and challenges that currently face those seeking action on the SDOH. Key Messages 1. Public health advocacy associations serve as important drivers for health equity and the social determinants of health. 2. There are lessons to be learned from the history of the social determinants of health, to inform present and future challenges in this field. 3. The Canadian Public Health Association represents one example of an organization that has been fundamentally concerned with the social determinants of health (e.g., poverty, housing, income) since its 1910 establishment.