Jetons or jettons are tokens or coin-like medals produced across Europe from the 13th through the 18th centuries. They were produced as counters for use in calculation on a counting board, a lined board similar to an abacus. Jetons for calculation were commonly used in Europe from about 1200 to 1700, and remained in occasional use into the early nineteenth century. They also found use as a money substitute in games, similar to modern casino chips or poker chips.

Thousands of different jetons exist, mostly of religious and educational designs, as well as portraits, the last of which most resemble coinage, somewhat similar to modern, non-circulation commemorative coins. The spelling "jeton" is from the French; it is sometimes spelled "jetton" in English.

The Romans similarly used pebbles (in Latin: calculi "little stones", whence English calculate). Addition is straightforward, and relatively efficient algorithms for multiplication and division were known.

The custom of stamping counters like coins began in France, with the oldest known coming from the fiscal offices of the royal government of France and dating from around the middle of the 13th century. From the late 13th century to the end of the 14th century, jetons were produced in England, similar in design to contemporary Edwardian pennies. Although they were made of brass they were often pierced or indented at the centre to avoid them being plated with silver and passed off as real silver coins. By the middle of the 14th century, English jetons were being produced in a larger size, similar to the groat.

Throughout the 15th century competition from France and the Low Countries ended jeton manufacture in England, but not for long. Nuremberg jeton masters initially started by copying counters of their European neighbours, but by the mid 16th century they gained a monopoly by mass-producing cheaper jetons for commercial use. Later – "counter casting" being obsolete – production shifted to jetons for use in games and toys, sometimes copying more or less famous jetons with a political background.

Mints in the Low Countries in the late Middle Ages in general produced the counters for official bookkeeping. Most of them show the effigy of the ruler within a flattering text and on the reverse the ruler's escutcheon and the name or city of the accounting office.

During the Dutch Revolt (1568–1609) this pattern changed and by both parties, the North in front, about 2,000 different, mostly political, jetons (Dutch: Rekenpenning) were minted depicting the victories, ideals and aims. Specifically in the last quarter of the 16th century, where geuzen or "beggars" made important military contributions to the Dutch side and bookkeeping was already done without counters, the production in the North was just for propaganda.

The mints and treasuries of the big estates in Central Europe used their own jetons and then had a number of them struck in gold and silver as New Year gifts for their employees, who in turn commissioned jetons with their own mottoes and coats-of-arms. In the sixteenth century the Czech Royal Treasury bought between two and three thousand pieces at the beginning of each year.