Pictured left are probation officers Bert Bellman, Margaret Weston & Philip Main John Scott (left), Jessica Spencer & John Paul),

Probation Officer began in 1959 on ATV (Associated Television) and ran until 1962. The hour-long episodes use a semi-documentary format and deal with the problems encountered on a daily basis by the probation service professionals. Three of the main characters in the series are, Philip Main (John Paul), Margaret Weston (Jessica Spencer), and Bert Bellman (John Scott).

John Paul stars as probation officer Philip Main from the very first episode broadcast in September 1959. Another regular cast member from the early days of the series is John Scott (probation officer Bert Bellman). Jessica Spencer (probation officer Margaret Weston) joined the series in the latter part of 1960. Also in the regular team is probation officer Steven Ryder (Bernard Brown).

The series embraces the work of various law enforcement agencies empowered to punish all types of crime and general law-breaking in the UK. The early series are set in and around an assizes court, with later episodes focusing on the juvenile court system, followed by the work carried out by the magistrate's courts. Although the series is intended as entertainment, it does wherever possible focus on important problems encountered not only by probation officers but also by the general public.

One of the episodes of Probation Officer is about a man who tries to assist a young lady who is receiving the unwanted attention of three young thugs on an underground train, but while the other passengers are held back the would-be knight-in-shining-armour is savagely beaten-up. As a consequence of his injuries the man loses his job because he is unable to work, thus illustrating the fact that although it is everyone's duty to be vigilant and help a fellow citizen if possible, if any injury is sustained in the process the government can give no financial assistance.

Probation Officer gained the unusual distinction for a television series by having one episode shown to to a group of peers in the House of Lords. The life peer Lord Stonham described the series as "a valuable social service" and in a statement published in a television magazine during the original run of the series, Lord Stonham says "Probation Officer does not preach, because you would not listen. But, while you watch these fascinating stories of other people's troubles, you get a picture painted with pinpoint accuracy of our penal system and its fault." He continues "It [Probation Officer] plays a leading part in persuading the nation to try to make good citizens of those who would otherwise be lost and enables those who have broken the law and paid the price, to find themselves again."

The writer of the early scripts of Probation officer and creator of the characters Philip Main and Bert Bellman is Julian Bond. Before commencing work on the scripts, Julian Bond spent three months researching into exactly what the work of the probation service involves. Bond, who also wrote some of the later scripts for the series, visited courtrooms, met with probation officers and those in the officers' care. The character of Philip Main is a composite of several probation officers Julian Bond met in the course of his research.