Instead, the president enjoyed a dinner with the US Ambassador at his residence in the Phoenix Park yesterday evening, before travelling directly to Dublin Airport.
His 29-vehicle cavalcade arrived in the airport shortly before 9.15pm last night. Air Force One started taxiing down the runway 10 minutes later and took off, bound for London, at 9.28pm.
Dan Rooney, the US Ambassador, was the only official on the tarmac to see him off.
Air Force One took off from the main runway, with the Irish Aviation Authority "sterilising" the Irish airspace for approximately 20 minutes, although it did not have a knock-on effect on regular flights.
The Chinook helicopters were due to fly out later, while a Galaxy aircraft was also due into Dublin Airport last night to collect the US government vehicles.
Mr Obama had been due to spend the night at the plush Merrion Hotel, adjacent to Government Buildings, in the heart of Dublin.
Tight security had been installed with the entire street sealed off, a marqee erected outside and dozens of gardai patrolling the area.
Garda detectives had already begun examining the tall buildings in the neighbourhood with binoculars to seal off the hotel just moments before his travel plans were changed.
"Due to a recent change in the trajectory in the plume of volcanic ash, Air Force One will depart Ireland for London tonight," deputy press secretary Josh Earnest said shortly after Mr Obama came off the stage at College Green.