An announcement was made on the flight from Gatwick Airport after 47-year-old Paul Norbury fell ill some 45 minutes into the journey with 430 passengers on board.
The Virgin tycoon's 26-year-old daughter, Holly, a qualified doctor, came forward to offer her help before checking his pulse and blood pressure, administering oxygen and speaking to medical experts on the ground. A Virgin Atlantic spokesman said a decision was taken by Holly and medical staff on the ground to divert the flight to Ireland's Shannon Airport for Mr Norbury to attend Ennis General Hospital by ambulance.
Sir Richard said: "I'm incredibly proud of Holly and pleased that her qualifications were able to save the life of one of our passengers." Among the passengers on board the Boeing 747, Virgin Flight VS33, was former Formula 1 boss Eddie Jordan who later contacted Sir Richard to congratulate his daughter's actions.
The Virgin Atlantic spokesman said: "Holly tended to the patient and in conjunction with the medical team on the ground decided that he was suffering a mild heart attack and he needed to get to hospital as soon as possible."
Within an hour of the landing at Shannon Airport, the Boeing continued on to Antigua. Holly is due to spend Christmas on Sir Richard's private island, Necker.
She studied at University College London before passing her exams last year and starting her first job at Chelsea and Westminster Hospital. She is now involved in running Virgin Healthcare. The Virgin Atlantic spokesman said: "It's the ultimate case of the flying doctor."