Wervik (Dutch: [ˈʋɛrvɪk]; French: Wervicq [wɛʁvik]; West Flemish: Wervik [ˈβærvɛk]; Latin: Viroviacum) is a city and municipality located in the Belgian province of West Flanders. The municipality comprises the city of Wervik and the town of Geluwe. On January 1, 2014, Wervik had a total population of 18,435. The total area is 43.61 km² (16¾ sq. mi.) which gives a population density of 423 inhabitants per km² (1095 per sq. mi.). The area is famous for its excellent tobacco and has a tobacco museum. The town is separated from its French counterpart Wervicq-Sud by the river Lys.

Wervik is one of the oldest towns in Belgium.^{[citation needed]}

Stone Age artefacts, flint axes and spearheads, were found in the district of Bas-Flanders and the site Oosthove. The archeological excavations at de Pioneer in 2009 yielded traces of inhabitation from the Iron Age to the Roman Period.

Wervik was probably a settlement of the Menapians led by the chief Virovos, at a small height along the banks of the Lys (current Island Balokken). This is still unproven. At the time of the conquest of Gaul by Caesar, a Roman stopping place was built next to the Celtic village. The Roman settlement was registered on Roman road maps from the 3rd to 4th century under the name Viroviacum (Itinerarium Antonini) or Virovino (map of Peutinger). Viroviacum was located on the Roman road between Cassel and Bavay. Remains from that period are still being found regularly in Wervik. Excavations at Saint Martin's Square in the centre exposed the foundations of the old Saint Martin's church, which was partly built with Roman waste materials. According to some historians this was formerly a temple dedicated to Mars or Priapus. This is still unproven.

In the 13th century the population of Belgium rose sharply, thanks to the great heyday of the textile trade which penetrated international markets up to the Far East. In 1327 the city was taken by Philip of Valois and partially destroyed.

During the Ghent uprising of 1382, Wervik was an outpost of the army of Philip van Artevelde during the Battle of Westrozebeke. The rebellion failed, and the city was plundered by the Bretons and reduced to ashes. The Saint Medardus church had to be rebuilt completely. Wervik had not yet fully recovered when a major fire in 1400 destroyed the whole town again. Of the 820 dwellings there only 20 remained. Jan Zonder Vrees gave Wervik a market hall in 1401, as an incentive for recovery and revival. In 1436 part of the garrison of Calais invaded Wervik and again burnt the town to ashes, in 1440 the town was burnt again. The many successive fires were mainly because most houses were built of wood and straw, and that the town had no protection against attacks as it was never walled. After the succession of fires the town was attacked by the plague. In the years 1436 and 1468 the population was decimated by the epidemic.

In the middle of the 16th century finally a quieter period began for Wervik. Prosperity had vanished and the population had dropped to about 3000 inhabitants. During the religious quarrels, the Saint Medardus church was badly damaged and today still bears the traces of the iconoclastic. The Geuzen burnt the church in 1579.

In the 17th century the entire region was affected by the ongoing annexation attempts of the French king Louis XIV. Wervik was taken by the French in 1668 and was later annexed to the Spanish crown in 1678. After the Peace of Nijmegen treaty in that year, Wervik became French territory again. The continuous impoverishment of the town left it with only 3172 inhabitants.