The Soloheadbeg ambush took place on 21 January 1919, when members of the Irish Volunteers ambushed Royal Irish Constabulary (RIC) officers who were escorting a consignment of gelignite explosives at Soloheadbeg, County Tipperary. Two RIC officers were killed and their weapons and the explosives were stolen. The Volunteers acted on their own initiative and had not sought authorisation for their action. As it happened on the same day that the revolutionary Irish parliament first met and declared Ireland's independence, it is often seen as the first engagement of the Irish War of Independence.

The Irish Volunteers, also known as the Irish Volunteer Force or the Irish Volunteer Army, was a paramilitary organisation established in 1913 by nationalists and republicans in Ireland. It was ostensibly formed in response to the formation of its Irish unionist/loyalist counterpart the Ulster Volunteers in 1912, and its declared primary aim was "to secure and maintain the rights and liberties common to the whole people of Ireland". Its ranks included members of the Conradh na Gaeilge, Ancient Order of Hibernians, Sinn Féin and the Irish Republican Brotherhood. Increasing rapidly to a strength of nearly 200,000 by mid-1914, it split in September of that year over John Redmond's support for the British war effort during World War I, with the smaller group opposed to Redmond's decision retaining the name "Irish Volunteers".