The partnership will cover the next two Rugby World Cups and will see Eden Park kit out all members of the national squads, ranging from the seniors through to the Under-18s, the management teams and backroom staff.
Franck Mesnel, the former French international and founder of Eden Park, said: "Eden Park has come a long way since 1987, when five Racing Club de France rugby players decided to design a set of rugby shirts for our friends.
"Irish rugby is all about passion and flair and we aim to recreate this flair and commitment to excellence in the formalwear that we will supply the squad."
Pat Fitzgerald, IRFU Junior Vice President, commented: "Eden Park's rugby heritage and attention to detail make it an ideal partner for the IRFU.
"Being founded by ex-international rugby players means they know exactly what a rugby player requires and we are delighted Eden Park has committed to a long term contract with the Ireland rugby squad."
With the Rugby World Cup in New Zealand rapidly approaching, the Irish squad will be heading Down Under decked out in bespoke plain navy suits hand-tailored to their individual measurements and accompanied by a white cotton shirt and green silk tie.
There will be an unprecedented attention to detail in the suits, including rugby kit inspired silk suit linings and the use of luxurious and comfortable fabrics.
Ireland captain Brian O'Driscoll said: "Success on the rugby pitch starts with thorough preparation and the suits that Eden Park has provided the squad with will undoubtedly help us look and feel professional and smart off the pitch.
"The formalwear looks and feels great and we are looking forward to wearing them in New Zealand as we represent our country at the Rugby World Cup."