Arguing that criminology has thus far inadequately theorised militarism as it relates to the prison system, this agenda‐setting article introduces the ‘prison‐military complex’ as a means to initiate examination of militarism in relation to institutions and practices of incarceration. In so doing, it identifies a key knowledge gap vis‐à‐vis the role of ex‐military personnel employed as prison staff; and poses key questions about the ways in which military staff and military methods are being directly targeted as a means to reform a prison service reeling from unprecedented levels of violence, self‐harm, riots, and escapes. Encouraging criminologists to think beyond stereotypical ideas about the military, the article revolves around a multiscalar articulation of the prison‐military complex, discussed here as it relates to reform of the prison system as a whole; the rehabilitation of offenders; and individuals’ ex‐military transitions to civilian life.