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 and Pte Damian WRIGHT, 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.