Researchers have shown how UN stabilization peace operations mix liberal and illiberal goals and strategies. Yet, further research is needed to theorize and comprehend illiberal peacebuilding features of stabilization operations. This article fills this gap by demonstrating how UN stabilization operations wield illiberal peacebuilding practices. Building upon previous scholarship, we understand illiberal peacebuilding both as an approach and outcome which is oriented by and helps diffuse illiberal norms in the societies where illiberal peacebuilding is instrumentalized by local, regional and international actors. We frame UN stabilization operations in the CAR, the DRC, and Mali as illiberal peacebuilding processes infused with illiberal strategies and show that liberal actors can engage with illiberal strategies for peace promotion. We also analyse peace agreements that accompany these missions as illiberal peacebuilding outcomes and show how these are shaped by illiberal norms. Our key finding is that a set of illiberal norms – exclusion, violence, power inequality and authoritarianism – are central for both UN stabilization operations and peace agreements signed in CAR, DRC and Mali. Therefore, we challenge the UN discourse that stabilization is a needed first step towards liberal and inclusive peace agreements.