爱尔兰联合银行(ISEQ: ALBK, LSE: ALBK, NYSE: AIB, FWB: AIB)成立于1966年，现有员工5万人，其业务现已覆盖到美国、英国、波兰等多个国家和地区，总部设在都柏林，是爱尔兰最大的金融公司。

爱尔兰联合银行是爱尔兰最大的外汇交易公司，其影响力远远超过爱尔兰银行。爱尔兰联合银行在纽约、伦敦和都柏林股市上总共有10万股民。总行由6个部分组成，具体包括：爱尔兰共和国爱尔兰联合银行，该行的主要业务是处理国内保险和金融以及贷款业务；英国及北爱尔兰的爱尔兰联合银行，主要由英国的金融集团和北爱的第一信托银行组成；爱尔兰联合银行国际银行负责国际投资业务；波兰爱尔兰联合银行，负责最近刚刚收购的两家银行的运作；爱尔兰联合银行企业网络是最近刚刚创立的，负责高科技发展。

爱尔兰联合银行美国分行爱弗斯特是美国五十大银行之一，现有职员6000人，在马里兰州和宾州有250个次一级支行，并在纽约、芝加哥、洛杉矶、费城、亚特兰大和旧金山都开设有办公室。

Allied Irish Banks is usually referred to, both inside and outside the company, as simply AIB and often incorrectly as "Allied Irish Bank". In Northern Ireland however, the bank is known as First Trust Bank, while in Great Britain, it is called "Allied Irish Bank (GB)" - the only part of the operation where the full name, in the singular, is still in day-to-day use.

Initially, the bank operated under the names of its former constituent companies, alongside a new AIB logo, a circle divided in three with an "A" at the centre. From 1970, these were replaced by "Allied Irish Banks". In 1990, AIB introduced a new logo (prompted, it was said in some quarters, by the remarkable similarity between its previous logo and that of Mercedes-Benz.). Since then, the bank has preferred to be referred to as simply "AIB", though "Allied Irish Banks plc" remains its legal name.