The venue also grossed over $50.7m (€36.26m) in 2011.
The 670,846 represents a 2pc increase on the 656,174 tickets that were sold at the O2 in Dublin in 2010.
The most popular music arena in the world last year was the O2 in London where 1.92 million fans attended concerts. Madison Square Garden was ranked eighth.
The 14,500-capacity O2 in Dublin is jointly owned by Dublin businessman, Harry Crosbie and the Los Angeles-based concert promoters, Live Nation Inc which counts U2, Madonna and the Rolling Stones amongst its acts.
Dublin's O2 staged 82 box-office gigs last year and Pollstar stated that the average gross per concert was over $1m (€785,388). Pollstar said the average percentage capacity sold per concert at the O2 last year was 90pc, 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.
The figures show that each George Michael gig grossed $1.38m (€1.08m) in receipts, with the two November nights grossing $2.768m (€2.17m).
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 top grossing run at the O2 last year was not recorded by a pop star, but by singers from the hit US TV series, 'Glee'.
The figures show that ' Glee's four sold-out shows last July grossed $3.57m (€2.8m).
Westlife's sold-out five-night run in April grossed $3.3m (€2.59m), while comedian Peter Kay's six nights in April grossed $3m (€2.35m).
The returns show 'X Factor Live's five shows grossed $2.58m (€2.02m), with Roger Waters's two performances in May grossing $2.3m (€1.8m) while Kylie grossed $2.1m (€1.64m) from her two shows in March. Two separate performances by Rihanna in October and November grossed $2.1m (€1.64m).
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 O2 venue re-opened in December 2008. O2 paid €25m for naming rights in a 10-year deal.
According to the Pollstar survey, the Manchester Evening News Arena was ranked second in the world with 1.2 million tickets sold; with Sportpaleis Antwerpen in Belgium coming third and the Rod Laver arena in Melbourne, Australia coming fourth.