The 9th Battalion of the Duke of Wellington's Regiment (West Riding) was a First World War battalion in the Territorial Army.
The battalion was raised in September 1914 at Halifax from new recruits. It initially formed part of the 52nd Brigade of the 17th (Northern) Division in the K2 Group of Kitchener's New Army.
Following training, the battalion sailed to France in July 1915 and were deployed at Southern Ypres. They subsequently took part in battles at Albert, Delville Wood, Scrape, Passchendaele, St. Quentin, Bapaume, Amiens, Havrincourt, Epehy, Cambria, Selle, and Sambre.
The 9th Battalion was demobilised in January 1919.
For details of individuals who served in the 9th Battalion, see: