The growing popularity of Greta Thunberg has led an increasing number of pundits and scholars to consider her message to be an instance of ‘climate’ or ‘environmental’ populism. Following a qualitative content analysis of key speeches by the young activist, this paper challenges this view, and argues that her message is far from being a case of populism. On the contrary, it abides by a substantially different set of ideas that can be defined as technocratic ecocentrism. In particular, it is argued that rather than people‐centrism, anti‐elitism and vox populi, Greta Thunberg’s message is grounded on three different core ideas: ecocentrism, technocracy, and on the exaltation of the vox scientifica. However, whereas Thunberg’s technocratic ecocentrism is at odds with the foundations of the populist set of ideas, it shares a similar emphasis on monism, moralisation, a Manichean vision of the world, a critique of key features of the metapolitical status quo, and a tendency to personalisation.