State capture by wealthy elites is a widespread phenomenon in developing democracies, yet the mechanisms through which it works and the impact it has on political and policy outcomes remain poorly understood. In this research, I develop a network-based approach to studying captured legislatures and argue that, in the context of a competitive political environment and weak rule of law, oligarchs defend their wealth by promoting as members of parliament individuals who are linked to them via interpersonal ties. Using unique data and social network analysis, I uncover the hidden networks of interpersonal connections among nearly 1,000 legislators and oligarchs in Ukraine over the course of two parliamentary convocations (2014–2024). I then demonstrate that these networks facilitate the adoption of policies that align with oligarchs’ economic interests and shape policymaking more broadly. The study provides important insights for understanding money in politics, oligarchy, state capture, neopatrimonialism, legislative politics, and political representation.