Family farming has progressed and evolved over time, which has included changes in gender roles and the introduction of pluriactivity on many farms. The history of farming leads to the discussion of family farm entrepreneurs and on-farm diversification. Ontario is now home to a variety of on-farm diversification initiatives, including roadside fruit and vegetable stands; sugar bush educational experiences; various wineries, breweries and distilleries; small scale restaurants; wedding venues; concert venues; horse riding ranches; eco-adventure facilities, including zip lines and tree-top canopy adventures, children’s adventure farms and seasonal venues; dirt bike courses; overnight accommodations and much more. The land use planning regime applied in rural Ontario is primarily based on agriculture and farmland preservation. In 2016 the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) created the Guidelines on Permitted Uses in Ontario’s Prime Agricultural Areas (Guidelines), the first planning tool to assist local municipalities in creating opportunities for on-farm diversification. This dissertation examines the history and evolution of family farms including current day on-farm diversification trends. This dissertation describes the current planning policy regime in Ontario that allows for on-farm diversification opportunities and requirements for the preservation of agricultural lands by examining the Provincial Policy Statement and outlining the purpose and effect of Official Plans, Zoning By-laws and municipal land use processes. Then, independent research through surveys, interviews and focus groups with Ontario farmers and Professional Planners is summarized and analyzed to provide recommendations on balancing on-farm diversification and agricultural preservation. It is discovered that the OMAFRA Guidelines are an excellent and useful tool in creating on-farm diversification opportunities while also meeting Ontario’s legislation to protect prime agricultural areas. However, the OMAFRA Guidelines are significantly underutilized, not interpreted or implemented consistently across Ontario and require updating and the possible creation of a user tool to assist Ontario farmers and Professional Planners in creating responsible and resilient new land uses on family farms.