Redut, also known as Redoubt, Redut-Antiterror or Centre R, formerly known as "Shield", is a Russian Private Military Company (PMC) that is a part of the "Antiterror-family" — which consists of similarly named PMCs that protect commercial operations of Russian companies. It is currently deployed by Russia in the Russian invasion of Ukraine. According to an RFE/RL investigation, "Redut" is fully controlled and managed by GRU.

A private military company (PMC) or private military and security company (PMSC) is a private company providing armed combat or security services for financial gain. PMCs refer to their personnel as "security contractors" or "private military contractors".