This short piece provides an analytic framework for thinking about prison oversight. Noting the term “oversight” lacks a clear meaning, the author distinguishes several important functions provided by oversight mechanisms, including regulation, audit, accreditation, investigation, legal, reporting, and monitoring. “Oversight” is really an umbrella concept that encompasses each of these functions, but each of these functions need not be served by the same oversight body. Instead, the focus should be on ensuring that each function is served effectively in every jurisdiction. The ideal is to have a layered system of correctional oversight in which there is a range of effective internal accountability measures and robust external oversight mechanisms.