The North Irish Horse was a yeomanry unit of the British Territorial Army raised in the northern counties of Ireland in the aftermath of the Second Boer War. Raised and patronised by the nobility from its inception to the present day, it was one of the first non-regular units to be deployed to France and the Low Countries with the British Expeditionary Force in 1914 during World War I and fought with distinction both as mounted troops and later as a cyclist regiment, achieving eighteen battle honours. The regiment was reduced to a single man in the inter war years and re-raised for World War II, when it achieved its greatest distinctions in the North African and Italian campaigns. Reduced again after the Cold War, the regiment's name still exists in B Squadron, the Scottish and North Irish Yeomanry and 40 Signal Squadron, part of 32 Signal Regiment.

Yeomanry is a designation used by a number of units and sub-units in the British Army Reserve which are descended from volunteer cavalry regiments that now serve in a variety of different roles.