Over the past half-century, the number of adults under criminal justice supervision increased precipitously in some Western countries, with carceral control in the United States reaching an unprecedented scale. While much of the scholarly attention has been focused on the development of mass incarceration, new research focuses on the parallel expansion of mass probation and, more broadly, mass supervision. In the United States, the number of adults on probation and parole supervision increased from one million in 1980 to a peak of nearly 5.1 million in 2007, more than double the number of inmates in local, state, and federal jails and prisons. Estimates from Europe in the late 2000s suggest that there were approximately 3.5 million on community sanctions, compared to 2 million incarcerated. Individuals on these sanctions serve out their initial sentences (or remaining time after release from jail or prison) while residing in the community under the supervision of a probation or parole officer. As scholarship increasingly focuses on the expansion of community supervision, we are learning more about this form of punishment. Probationers and parolees are subject to a variety of conditions, including reporting regularly to their supervising officers, finding and maintaining employment, avoiding drug use and re-arrest, participating in therapeutic programs, and paying fines and fees. Failure to comply with the demands of supervision may result in variety of penalties, up to a return to custody for the entire length of the suspended prison sentence. Thus, while probation and parole are often framed as acts of leniency—allowing individuals to avoid incarceration and/or exit early—they can be experienced as quite punitive. In other words, the official discourses and everyday practices of supervision blend both punitive and rehabilitative elements. The composition of this blend varies significantly across countries, states, local departments, individual officers, and the officer-supervisee relationship. This variation has produced a kaleidoscope of different practices, all under the banner of community supervision.