The National Volunteers is the name taken by the group of the Irish Volunteers that sided with Irish Party leader John Redmond after the group split in the wake of the question of the Volunteers' role in World War I.

While Redmond took no role in the creation of the Irish Volunteers, when he saw how popular they had become he realized an independent body of such magnitude was a threat to his authority as leader of the Irish Parliamentary Party, and therefore sought control of the organization. Eoin MacNeill, along with Sir Roger Casement and other leaders of the Irish Volunteers, had indeed sought Redmond's approval of and input in the organization, but did not want to hand control over to him. In June, 1914 Redmond insisted the Volunteers accept 25 members of his choosing to the 27 member Provisional Committee (as some of the standing members were already Redmond supporters this would have given him control). The motion was bitterly opposed by the radical members of the committee (mostly members of the Irish Republican Brotherhood), notably Patrick Pearse, Sean MacDermott, and Eamonn Ceannt, but was carried nevertheless in order to prevent a split. With the support of the Irish Party the Volunteer organization grew dramatically.

Following the outbreak of World War I in August, and the successful placement of the Third Home Rule Act 1914 on the statute books, Redmond made a momentous speech in Woodenbridge, County Wicklow on September 20, in which he called for members of the Volunteers to enlist in Irish regiments of the New British Army, his motives twofold. Firstly, it was in the future interest of an All-Ireland Home Rule settlement to support the war cause, also joining the Ulster Volunteers who offered immediate support enlisting in their 36th (Ulster) Division). Seconly, he reminded the Irish Volunteers that when they returned after an expected short war at the end of 1915, they would be an armed army capable of confronting the outcome of the partition bill forced through by Sir Edward Carson, leader of the Ulster Unionists, as an ammendmment to the Home Rule Act. Nearly all of the original leaders of the Volunteers utterly rejected this notion, and dismissed Redmond's appointees, who then formed the National Volunteers.

The vast majority of the membership remained loyal to Redmond, keeping some 175,000 members, leaving the Irish Volunteers with a mere estimated 13,500. Most members of the National Volunteers as well as other Irishmen following the call of their parliamentary leaders, such as William O'Brien MP. and D.D. Sheehan MP., joined the 10th (Irish) Division or the 16th (Irish) Division. Redmond's expectations were however overtaken by events to follow, the unexpected prolonged war, notably the Easter Rising and then the results of the general elections in December 1918.

The members of the National Volunteers thus playing little role in the political aftermath, the ensuing Anglo-Irish War allowing Ulster's Orangemen set up a Home Rule government as the Parliament of Northern Ireland under the Government of Ireland Act, 1920, without any intervention from the south.

Following the Anglo-Irish Treaty on terms similar to the Home Rule Act, the Irish Free State was founded, followed by de Valera's anti-treaty civil war in 1922. In this third Irish war within a decade many earlier members of the National Volunteers played a decisive role as returned ex-British Army officers and ex-servicemen of former famous Irish Regiments, in forming General Michael Collins's new Free State Force. Their military discipline and professional experience saved the new state from falling into anarchy and chaos, bringing the anti-treaty revolt under control a year later.