Justice of the Common Pleas was a puisne judicial position within the Court of Common Pleas of England and Wales, under the Chief Justice. The Common Pleas was the primary court of common law within England and Wales, dealing with "common" pleas. It was created out of the common law jurisdiction of the Exchequer of Pleas, with splits forming during the 1190s and the division becoming formal by the beginning of the 13th century. The court became a key part of the Westminster courts, along with the Exchequer of Pleas and the Court of King's Bench, but with the Writ of Quominus and the Statute of Westminster, both tried to extend their jurisdiction into the realm of common pleas. As a result, the courts jockeyed for power. In 1828 Henry Brougham, a Member of Parliament, complained in Parliament that as long as there were three courts unevenness was inevitable, saying that "It is not in the power of the courts, even if all were monopolies and other restrictions done away, to distribute business equally, as long as suitors are left free to choose their own tribunal", and that there would always be a favourite court, which would therefore attract the best lawyers and judges and entrench its position. The outcome was the Supreme Court of Judicature Act 1873, under which all the central courts were made part of a single Supreme Court of Judicature. Eventually the government created a High Court of Justice under Lord Coleridge by an Order in Council of 16 December 1880. At this point, the Common Pleas formally ceased to exist.

The Court of Common Pleas, or Common Bench, was a common law court in the English legal system that covered "common pleas"; actions between subject and subject, which did not concern the king. Created in the late 12th to early 13th century after splitting from the Exchequer of Pleas, the Common Pleas served as one of the central English courts for around 600 years. Authorised by Magna Carta to sit in a fixed location, the Common Pleas sat in Westminster Hall for its entire existence, joined by the Exchequer of Pleas and Court of King's Bench.