Belfries are a kind of bell tower or civic tower common in Belgium and Northern France. The oldest, and one of the best preserved, belfry in Belgium is located in Tournai.

The freestanding bell tower was built in 1188, when Tournai was given the independence from local counts and became a subject of the French crown. With this distinction came the right to build a bell tower. Originally, the tower was about 30 meters (98 feet) tall, with a square section and crenelated parapet. It served more as a watchtower than as a bell tower, but is also served as a jail until the 19th century.

In the late 13th century, the Tournai Cathedral was being built near the belfry. The height of the massive new religious building obstructed the view from the tower, so in 1294 additions to the belfry more than doubled its height, which currently stands at 72 meters (236 feet). The older structure was adorned with four towerlets at the corners and various statues. The clear difference between the oldest part and the newer one can be seen to this day.

A fire damaged the building in 1391 but it was later repaired. Over the following centuries the structure remained largely the same, except from some occasional restorations and additions. In 1999 it was designated a UNESCO World Heritage Site along with many other belfries in the region.