This paper examines the emergence and operations of the Wagner Group in Ukraine between 2014 and 2018, situating the private military company (PMC) within the broader framework of Russia’s hybrid warfare strategy. The analysis demonstrates that Wagner was not an independent mercenary organisation, but rather a state-linked proxy used to advance Moscow’s geopolitical objectives while maintaining plausible deniability. Drawing on academic studies, investigative journalism, and reports by international organisations, the paper traces Wagner’s evolution from its early deployment during the annexation of Crimea to its expanded role in the Donbas conflict. Wagner’s activities included direct combat support, training and reinforcement of separatist militias, political assassinations, and the elimination of dissent within the self-proclaimed republics. These actions underscored the group’s dual function as both a combat force and an enforcer of Kremlin interests. The findings suggest that Wagner blurred the boundaries between state and private actors, providing Moscow with a flexible instrument to destabilise Ukraine while avoiding direct accountability. Furthermore, this case illustrates how PMCs can serve as key components of modern hybrid warfare, combining military, political, and informational dimensions. Wagner’s trajectory in Ukraine laid the foundation for its subsequent global expansion, highlighting its strategic utility for Russia in conflict zones beyond Eastern Europe.