A High Court date has yet to be set for a hearing to decide who should have power of attorney over the ageing icon’s decisions.
The 92-year-old actress had made Glengarriff her retirement home and it was thought she was too frail to fly.
However, she arrived in the US on Saturday and in a brief comment to her fan website said she had an “excellent” flight both physically and emotionally.
It also said she was looking forward to holiday and family time.
Ms O’Hara has this year had to deny she was the victim of elder abuse, undergo tests to assess her state of mind, and parted company with a number of long-time advisers and staff.
Before the summer the High Court was asked to grant enduring power of attorney to her former personal assistant, Carolyn Murphy, who she first asked to manage her affairs seven years ago.
The Dublin-born star left Glengarriff without any notice. A statement said Ms O’Hara had arrived in the US in the company of her grandson Conor Beau Fitzsimons.
It also said she had “left with the blessings of her only daughter Bronywn”.
Mr Beau Fitzsimons was in Cork earlier this year and flanked Ms O’Hara at a June press conference which made a series of allegations about Ms Murphy and the foundation established to honour the actress’s legacy.
The foundation later opened its books to defend itself and account for money that had been spent and the vision it had for a proposed €13m legacy centre.
Ms O’Hara’s stepson, Chris Blair, has said he supports what the foundation was trying to achieve.
Despite the impending court date there had been speculation the move out of the country was imminent when removal vans were spotted at her West Cork home.