Roeselare (Dutch pronunciation: [ˈrusəlaː.rə], French: Roulers) is a Belgian city and municipality in the Flemish province of West Flanders. The municipality comprises the city of Roeselare proper and the towns of Beveren, Oekene and Rumbeke.

The name of the city is derived from two Germanic words meaning "reed" and "open space", i.e., a marsh in a forest glade. Roeselare's minor seminary is famous for having hosted the famous Flemish poets Guido Gezelle, Albrecht Rodenbach and missionary Jesuit Constant Lievens. The city is also home to the Rodenbach brewery.

Traces of early dwellings have been found in the area, including prehistoric flint tools, Gallo-Roman wells, and a small 9th century Frankish building. The first mention of Roslar dates from a document dated 821 or 822, whereby the former domain of the Menapii, also called the Rollare villa in later documents, was given to Elnon Abbey. According to legend, Baldwin Iron Arm, Count of Flanders, kidnapped Judith, the daughter of Charles the Bold in 862 in Senlis and brought her to a fortress that used to be where the present Rumbeke Castle stands. The Roeselare area soon became part of the County of Flanders. The rights to build fortifications and to hold a public market date from 957, during the lordship of Baldwin III.