Humanitarian interventions carried out by some national governments can help prevent or alleviate mass atrocities abroad. However, such interventions are arguably rendered less likely when domestic public support (as distinct from international endorsement) is absent or weak. This article focuses on public domestic support for different types of military and non-military humanitarian interventions. Specifically, we test theories of support for intervention based on the cultural similarity, public opinion, and statements from authority figures. We do so through two large-N survey experiments with samples from the Netherlands and Poland. The experimental vignettes manipulated (1) where the mass atrocities happen; (2) whether their community favors an intervention; (3) whether national leaders support an intervention. The findings showed that none of these manipulations had substantial and reliable influence on moral condemnation of atrocities or support for interventions. Exploratory analyses showed strong moral condemnation of atrocities in both studies and across conditions, but that support for interventions was typically lower and differed across the type of intervention. The analysis also showed that support for non-military interventions was related to knowledge about international politics and that support for military interventions was related to beliefs about the success of interventions.