Over the past few decades, a large variety of urban farms and projects have developed in the Global North. Urban agriculture addresses numerous challenges such as producing sustainable fresh food, educating people, and creating new jobs and skills. Urban agriculture is diverse in terms of location (rooftop, basement, underground, parking), activities (food production and/or services), and techniques (from low-tech to high-tech). These projects are created by entrepreneurs because they live in the city, want to change their environment, and promote sustainable practices. Faced with economic and environmental crises, public authorities at different levels and with various orientations reorganize the food system towards local production and consumption; they encourage the development of urban agriculture through a diverse range of policies. These public projects must be economically viable but can be created as socially oriented services based on food production and not only as sites of food production. Our empirical research based on the case studies of two original public urban farms, the Potager du Roi de Versailles and the Cité Maraichère de Romainville, uses the concept of the triple layered business model and highlights their sustainable strategy. Our evaluation of their economic, social, and environmental impacts tends to demonstrate not only their dependence on multiple interlinked public policies but also the justification of significant and recurring public funds for the general interest.