In 1881, D company of the 2nd Battalion, Notts Rifle Volunteers, met at the Armoury on Lime Tree Place. G. H. BRANSTON, captain; Geo. W. SPARKE, surgeon; Rev. Canon James T. BARTLET, M. A., chaplain; R. WATKINS, searjeant-instructor.
In 1912, Mansfield had two units of the Territorial Force:
- B Squadron of the Nottinghamshire Yeomanry (Sherwood Rangers), on Dame Flogan Street.
- D Company of the 8th Battalion, Nottinghamshire & Derbyshire Regt. (Sherwood Foresters), on Meeting House Lane.
The Americans opened a wartime hospital at King's Hill in 1942 to care for both American servicemen and German prisoners of war.
There is a War Memorial at Carr Bank Park that includes names the of men killed in the Korean war as well as relatives of L/Sgt David GREENHALGH (of Ilkeston, Derbyshire) and Pte Damian WRIGHT (from Mansfield), who both died in Afghanistan.
There are 100 Commonwealth War Graves at the Mansfield (Nottingham Road) Cemetery.
There are 7 Commonwealth War Graves at the Mansfield (Pleasley Road) Cemetery.