Ecofascism, sometimes spelled eco-fascism, is a term used to describe individuals and groups which combine environmentalism with fascism. Philosopher André Gorz characterised eco-fascism as hypothetical forms of totalitarianism based on an ecological orientation of politics. Similar definitions have been used by others in older academic literature in accusations of "environmental fascism".

Since the 2010s, a number of individuals and groups have emerged that either self-identify as "ecofascist" or have been labelled as "ecofascist" by academic or journalistic sources. These individuals and groups synthesise radical far-right politics with environmentalism, and will typically argue that overpopulation is the primary threat to the environment and that the only solution is a complete halt to immigration or, at their most extreme, genocide against various groups and ethnicities. Many far-right political parties have added green politics to their platforms. Through the 2010s, ecofascism has seen increasing support, and subsequently has seen increasing interest from researchers.