The Ulster Defense Association is a Protestant paramilitary organization and unionistic implied in the Conflit north-Irish. This group is classified like terrorist with the the United Kingdom as in Irish Republic. The UDA affirms to want to protect Northern Ireland from the catholic republican terrorists from WILL GO. Its military branches are called Ulster Freedom Fighters, that is to say UFF. Its terrorist activities cost the life many civilians Irish North, as to at least three members of WILL GO

In 2006, it was revealed that this group had infiltrated several maconnic cabins of Scotland.

Ulster Defense Association was created in September 1971 for chapeauter the whole of the groups which recognized themselves like defense associations of Ulster. Its first leader was Charles Smith. It could, with the " age of or" of its action, to gather to 40000 members. This organization was legal until August 10th, 1992. For this period, the UFF made many paramilitary acts, such as the assassination of Paddy Wilson, the leader of Social Demacratic and Labor Party (SDLP), in 1973.

The official position of the UDA/UFF during the Disorders was the following one: If WILL SUIT it stopped its violences, the UDA would make the same thing. However, if the British government announced its withdrawal of Northern Ireland, the UDA would act then like " one WILL GO inversée".

In 1987, the commander of the UDA John McMichael published an headed document " direction commun" , which proposed a consensual soution with the conflict in Northern Ireland, while maintaining the presence British. This document pled for an assembly sharing the capacities between Nationalistes and Unionistic, a constitution approved by all and a new Charter of the Rights (Bill off Rights). However, there is no consensus on the question of knowing if the UDA officially accepted this document in their official political line.

The large majority of the murders and attacks made by the UDA took place during the Eighties. The UDA also had recourse to the racket and the drug trafficking to be financed.