A carillon (US: KERR-ə-lon, UK: kə-RIL-yən) is a pitched percussion instrument that is played with a keyboard and consists of at least 23 bells. The bells are cast in bronze, hung in fixed suspension, and tuned in chromatic order so that they can be sounded harmoniously together. They are struck with clappers connected to a keyboard of wooden batons played with the hands and pedals played with the feet. Often housed in bell towers, carillons are usually owned by churches, universities, or municipalities. They can include an automatic system through which the time is announced and simple tunes are played throughout the day.

Carillons come in many designs, weights, sizes, and sounds. They are among the world's heaviest instruments, and the heaviest carillon weighs over 91 metric tons (100 short tons). Most weigh between 4.5 and 15 metric tons (5.0 and 16.5 short tons). To be considered a carillon, a minimum of 23 bells are needed; otherwise, it is called a chime. Standard-sized instruments have about 50, and the world's largest has 77 bells. The appearance of a carillon depends on the number and weight of the bells and the tower in which it is housed. They may be found in towers which are free-standing or connected to a building. The bells of a carillon may be directly exposed to the elements or hidden inside the structure of their tower.

The origins of the carillon can be traced to the Low Countries—present-day Belgium, the Netherlands, and the French Netherlands—in the 16th century. The modern carillon was invented in 1644 when Jacob van Eyck and the Hemony brothers cast the first tuned carillon. The instrument experienced a peak until the late-18th century, a decline during the French Revolution, a revival in the late 19th century, a second decline during the First and Second World Wars, and a second revival thereafter. UNESCO has designated 56 belfries in Belgium and France as a World Heritage Site and recognized the carillon culture of Belgium as an intangible cultural heritage.

According to counts by various registries, there are about 700 carillons worldwide. Most are in and around the Low Countries, though nearly 200 have been constructed in North America. Almost all extant carillons were constructed in the 20th century. Additionally, there are about 500 "non-traditional" carillons, which due to some component of its action being electrified or computerized, most registries do not consider to be carillons. A plurality are located in the United States, and most of the others in Western Europe. A few "traveling" or "mobile" carillons are fixed to a frame that enables them to be transported.