In the evolving discourse on climate change, the phenomenon of ‘whataboutism’ has emerged as a pervasive rhetorical strategy to deflect responsibility for the emissions of one’s own country by shifting blame to other nations. Given its nature, it is argued here that whataboutism may resonate particularly with nationalists, who exalt the concerns and priorities of their own country while downplaying those of other nations. Analyzing survey data from four European countries – Sweden, Germany, Spain, and Poland – this study demonstrates a strong and consistent relationship between nationalist attitudes and the extent to which people think that their own country should not act on climate change unless others do. The findings also show that climate whataboutism mediates the relationship between nationalist attitudes and opposition to climate policies. Hence, the results support the supposition that climate whataboutism discourses, driven by nationalist sentiments, permeates rightwing populist discourses to justify climate inaction.