The band, who have reformed for their first tour as a five-piece since 1995, are set to perform at two sold-out dates at Croke Park this week as part of their Progress tour and are booked into the Four Seasons in Ballsbridge.
A source told British newspaper The Sun: 'They stayed in the Merrion the last time they were here and loved it.
'But they also have rooms in the Four Seasons and a couple of other places booked just in case.'
The group - made up of Gary Barlow, Jason Orange, Mark Owen, Robbie Williams and Howard Donald - have apparently not made any big demands except privacy for their families.
But they are taking a crew of 287 when they arrive later today, which includes chefs as the band are shunning local food while they are in Ireland because of their strict tour diets.