Probation officers function as agents or officers of the courts. They serve under the court system as the enforcing arm of the court's sentence of someone who has been placed on supervised probation. There can be probation officers on the city, county, state or federal level (wherever there is a court of competent jurisdiction. Most jurisdictions require officers to have a four year college degree, and prefer a graduate level degree for full consideration for probation officer positions on the federal level.

Probation Officers investigate and supervise defendants who have not yet been sentenced to a term of incarceration. Typically, probation officers do not wear a uniform, but simply dress in business or casual attire. Probation officers are usually issued a badge/credentials and, in many cases, may carry concealed weapons and pepper spray for self protection or serving arrest warrants. Probation Officers with law enforcement powers, technically classified as peace officers, must attend a police academy as part of their training and certification.

Probation Agencies have a loosely based "paramilitary" command structure and are usually headed by a Chief Probation Officer or Director. The chain-of-command usually flows to Deputy Chief or Assistant Director, then to Supervisor or Senior Probation Officer, then to the line probation officer. Some Parole and Probation Officers supervise general caseloads with offenders who are convicted of a variety of offenses. Others hold specialist positions, and work with specific groups of offenders such as Sex Offenders, offenders sentenced house arrest or GPS Monitoring, cases with severe mental health, substance abuse, and violent histories.

A probation officer can perform any function assigned by the court. However, their usual mandate is to supervise offenders placed on supervision, and to investigate offender's personal and criminal history for the Court prior to sentencing. Probation and parole officers are required to possess excellent oral and written communication skills and a broad knowledge of the criminal justice system and the roles, relationships, and responsibilities distributed among the courts, the parole authority the Bureau of Prisons or Department of Corrections and/or local jails, police, substance abuse counseling and social services agencies, applicable case law, sentencing guidelines (if applicable) and the prosecutor. Additionally, they must have an ability to work with an extremely diverse population and wide variety of government agencies and community organizations and accept the potential hazards of working closely with a criminal population.