According to figures compiled by Pollstar, 670,846 music fans attended the Live Nation-operated venue in 2011.
This compares to the 616,874 who attended Madison Square Garden.
According to Pollstar, gross receipts from gigs at the O2 in Dublin last year topped $50.7m (€36.26m).
The 670,846 fans represent a 2% rise on the 656,174 tickets sold at the O2 in Dublin in 2010.
The most popular music arena in the world last year was the O2 in London, where 1.92m fans attended concerts. Madison Square Garden was ranked 8th.
The 14,500-capacity O2 in Dublin is jointly owned by Dublin businessman Harry Crosbie and Los Angeles-based concert promoters Live Nation, which counts U2, Madonna and the Rolling Stones amongst its acts.
Dublin’s O2 staged 82 gigs last year and Pollstar states the average gross per concert was over $1 million.
The US-based Pollstar say that the average capacity sold per concert at the O2 last year was 90%, with an average of 13,599 tickets sold for each concert.
The figures from the music industry journal are based upon returns from the concert venue operator and they show that the most lucrative night at the O2 last year was either of the two nights that George Michael performed. Each show grossed $1.38m in receipts with the two November nights grossing $2.768m.
The gross receipts for all concerts are shared between the promoter, artist and venue operator – they do not include revenues from merchandise or food and alcohol.
However, the highest grossing run at the O2 last year was not recorded by a pop star, but by singers from the hit US TV series Glee.
Their four sold-out shows in July grossed $3.57m.
Westlife sold out five night run in April and grossed $3.3m, with comedian Peter Kay’s six nights in April grossing $3m.
The data shows X Factor Live’s five shows grossed $2.58m, with Roger Waters’s two performances in May grossing $2.3m and Kylie grossing $2.1m from her two shows in March.
Two separate performances by Rihanna in October and November grossed $2.1m.
The main promoters behind the concerts last year were Aiken Promotions and MCD Productions.
The former Point Theatre closed in August 2007 to allow renovations be carried out and the €80m venue re-opened in December 2008.
In 2008, mobile phone company O2 agreed to pay €25m for the naming rights of the revamped Point in a 10-year deal.
According to the Pollstar survey, the Manchester Evening News Arena was ranked second in the world with 1.2m tickets sold, with Sportpaleis Antwerpen in Belgium coming third and the Rod Laver arena in Melbourne, Australia, coming fourth.