In mobilizing funds that selectively support non‐profits, foundations shape the political field. This study maps the funding relationships between foundations, ENGOs and think tanks in Canada and considers the implications for environmental politics. We examine foundation funding for different strains of environmental politics and policy‐planning and consider how ENGOs and think tanks are clustered as communities within a foundation‐centred support network. Of particular interest are ‘clean growth’ ENGOs that have emerged as key proponents of business‐friendly approaches to the climate crisis. We find that the ENGOs receiving large grants tend to be conservationist while the think tanks tend to be conservative. Communities in the network are divided between several clusters of corporate and family foundations supporting conservative think tanks, clean growth ENGOs and conservationist ENGOs, and a segment of the network in which one municipal and several family foundations, support more social‐ecological organizations, thereby facilitating more transformative visions and policies. Although few in number, clean growth organizations tend to receive giant donations, in some cases from corporate foundations aligned with the fossil‐fuel sector. Recent adoption of clean growth as governmental policy and its embrace within philanthropic missions could reshape the environmental field towards ‘clean growth’, as ENGOs seek funding and legitimacy.