XI Corps was formed on 29 August 1915.
Headquarters locations
- Formation: Saint-Omer
- 7 September 1915: Tilques
- 22 September 1915: Allouagne
- 25 September 1915: Noeux-les-Mines
- 3 October 1915: Vaudricourt
- 10 November 1915: Merville
- 5 March 1916: Hinges
- 22 November 1917: Béthune
- 24 November 1917: Busnes
- 28 November 1917: Lillers
- December 1917 to March 1918: in theatre of war in Italy
- By 1 April 1918: Hinges
- 9 April 1918: Robecq
- 10 April 1918: Norrent-Fontes
- 20 April 1918: Roquetoire
- 7 September 1918: Busnes
- 18 October 1918: Fromelles
- 19-20 October 1918: La Madeleine
- 29 November 1918: Labuissière (until at least the end of April 1919)
For more details about Labuissière see the page on I Corps headquarters

Commanding Officers
Lieutenant-General Richard C. B. Haking throughout hostilities (then appointed to International Armistice Commission at Spa)

12 November 1918: Major-General George F. Gorringe
Battles and Engagements
The Battles Nomenclature Committee of 1921 defined XI Corps as participating in the following:
First Army
The Battle of Loos (25 September – 8 October 1915)
The Actions of the Hohenzollern Redoubt (13-19 October 1915)
First Army
The Attack at Fromelles (19 July 1916)
First Army
The Battle of Estaires (9-11 April 1918)
The Battle of Hazebrouck (12-15 April 1918)
The Battle of Béthune (18 April 1918)
First Army
The Action of La Becque (28 June 1918)
The Advance in Flanders (18 August – 6 September 1918)
Fifth Army
The Final Advance in Artois (2 October – 11 November 1918)
After the capture of Lille and a ceremonial march through the city in late October 1918, the XI Corps flag used was sent to the Governor of Paris to display at the Lille monument there.