The Auxiliary Division of the Royal Irish Constabulary, generally known as the Auxiliaries or Auxies, was a paramilitary organization within the RIC. It was recruited in Britain from among World War I veterans who had served as army officers in the trenches. The theory behind this was that war would have "tempered" the officers and would make them good law enforcers. However, experience later showed that some were brutalized by their wartime experiences and some committed atrocities while performing their duties. Many had been highly decorated in the war and two, George Onions and James Leach, wore the Victoria Cross. They held the rank of Temporary Cadet. Originally intended to provide officers for the Black and Tans and paid £1 a day (twice the Black and Tan wage rates), they instead became a separate organisation.

Recruitment began in July 1920 and by November 1921 the division was 1,900 strong. The Auxies were nominally part of the RIC, but actually operated more or less independently in rural areas. Divided into companies (eventually fifteen of them), each about one hundred strong, heavily armed and highly mobile, they operated in ten counties, mostly in the south and west, where terrorist activity was considered to be greatest. Hurriedly recruited, poorly trained and with an ill-defined role, they soon gained a reputation for drunkenness and brutality worse than that of the Black and Tans. They wore either RIC uniforms or their old army uniforms with appropriate police badges. In February 1921 their commander, Brigadier-General Frank Crozier , himself a former officer of the Unionist paramilitary Ulster Volunteer Force, resigned in despair, utterly unable to discipline his men. They were and are often confused with the Black and Tans, and many atrocities laid at the door of the latter were in reality attributable to the Auxies. Disbanded along with the RIC in 1922, many Auxies joined the Palestine Police . As with the Black and Tans, they are still a contentious issue in Ireland.