Mr McManus hosted a private reception for the president, who was on a day-long visit to various parts of the county.
The lavish lunch was held at his current residence at Martinstown, which is a short distance from the huge mansion, which is nearing completion.
It is believed the president was very impressed by Mr McManus’s new mansion when she got a private viewing of the substantial estate.
The building, designed by Limerick architect Michael Healy, is bigger than Áras an Uachtaráin.
President McAleese took time out from her pubic engagements as she travelled between Newcastle West and Bruff to call in on the tycoon.
Her husband, Dr Martin McAleese, is a golfing friend of the Limerick gambling millionaire.
Mr McManus has done a deal with the local Staker Wallace GAA club to build a new state-of-the-art playing ground and pavilion in exchange for the club’s pitch which overlooks the new mansion. Sightseers have been using access to the GAA pitch in order to view the house.
The vast new McManus home covers 40,000 sq feet and its many features include a 200-seat cinema, a figure of eight shaped swimming pool and a special guest wing.
Although Mr McManus does not drink, except for an occasional glass of wine, the basement area will feature a fully stocked bar for guests who wish to enjoy a tipple.
And unlike Áras an Uachtaráin, the McManus family will have access to a special emergency area in the event of a security alert.
Mr McManus had hoped the mansion would be completed in time for the Ryder Cup in September to enable him host a house warming for friends such as Tiger Woods, Mark O’Meara and other top names in the world of golf.
Mr McManus proved himself on the golf course recently, winning the Dunhill cup for amateurs in Scotland when he partnered Padraig Harrington, who won the event outright.