The Royal Irish Rangers (23rd (Inniskilling), 83rd and 87th) was an infantry regiment of the British Army. It was formed in 1968 by the amalgamation of the three remaining Irish infantry regiments:

• 1st Battalion, Royal Inniskilling Fusiliers
• 1st Battalion, Royal Ulster Rifles
• 1st Battalion, Royal Irish Fusiliers

These three regiments together made up the North Irish Brigade, which was unique in the army at that time in containing regiments of different designations, in this case fusiliers and rifles; this made the descisions on amalgamation more difficult than those of the other large regiments formed at the time.

• Queen's Regiment
• Royal Regiment of Fusiliers
• Royal Anglian Regiment
• Light Infantry
• Royal Green Jackets

The discussions between the commanders led to the descision that neither title should be favoured, with the designation rangers being adopted, a title that had not existed in the British Army since 1922.

The Royal Irish Rangers came into being on 1st July 1968, a date initially known as Vesting Day (and then Ranger Day), emphasising that the traditions of the old regiments were vested in the new.

• The caubeen was adopted as the headgear for the new Regiment as all the former regiments had worn it
• The green hackle was formerly worn by the Royal Irish Fusiliers
• The Castle collar badges had been worn by the Royal Inniskilling Fusiliers
• The black buttons had been worn by the Royal Ulster Rifles
• The brown cross belt was a compromise between the brown Sam Browne belts worn by the Fusiliers and the black cross belt worn in the Rifles

The reorganisation of the infantry at that time meant that the new regiment would immediately lose one battalion, with the 3rd Battalion (former Royal Irish Fusiliers) being disbanded in December 1968.

With the creation of the Divisions of Infantry, the Royal Irish Rangers became part of the King's Division, along with regiments from the north of England. This continued until 1991 and Options for Change. Under this reorganisation, the Royal Irish Rangers were amalgamated with the Ulster Defence Regiment to form the new Royal Irish Regiment. Today, the name of the Royal Irish Rangers continues through the Territorial Army battalion in Northern Ireland, which comes under the operational control of the Royal Irish Regiment.