The Yser Front (French: Front de l'Yser, Dutch: Front aan de IJzer or IJzerfront), also known as the West Flemish Front, was a section of the Western Front during World War I held by Belgian troops from October 1914 until 1918. The front ran along the Yser river (IJzer) and Yser Canal (Ieperlee) in the far north-west of Belgium and defended a small strip of the country which remained unoccupied. The front was established following the Battle of the Yser in October 1914, when the Belgian army succeeded in stopping the German advance after months of retreat and remained largely static for the duration of the war.
During the early campaigns of 1914, the Belgian army had been pushed out of the fortified cities of Liège, Namur and Antwerp by the German advance. Although they succeeded in delaying the Germans at some actions, they were forced to withdraw, first to Antwerp, and into the far north-west of Belgium. By October 1914, the Belgian forces were holding a position along the Yser and Ieperlee canal. After months of retreat, the Belgians forces were considerably reduced and were exhausted. They flooded a large expanse of territory in front of their lines, stretching as far south as Diksmuide. Between 16 and 31 October, the Belgians held off the German army at the Battle of the Yser, suffering 3,500 killed and 15,000 wounded. The Battle of the Yser established a front line which would endure until 1918.
The Yser Front stretched along a distance of around 30 kilometres (19 mi) from the Belgian North Sea coast between Nieuwpoort and Westende, stretching south-east along the Ieperlee, encompassing both Ramskapelle and Pervijze. From Pervijze, the line then arched south-east between the Yser and Ieperlee, down to Oudekapelle and Reninge. Diksmuide had fallen to German forces shortly before the Battle of the Yser.