The 3Arena is an indoor amphitheatre with a capacity of 13,000 located at North Wall Quay in the Dublin Docklands in Dublin, Ireland. The 3Arena opened on 16 December 2008. It was built on the site of the former Point Theatre, a smaller music venue which operated from 1988–2007, retaining only some of the outer facade. The Point Theatre was branded as “The Point Depot”, in recognition of its original role as a railway goods handling station.

From 2008 to 2014, the 3Arena was known as The O2. Its capacity of 13,000 makes it the largest indoor arena in Ireland. The venue was rebranded on 4 September 2014 as the 3Arena due to the takeover of O2 Ireland by Three Ireland.