The X Factor judge was a quarter of the way to Cape Town when 11 BA staff were taken ill.
Barlow was winging his way to SA to film a new ad for Marks & Spencer.
But just three hours into the 12-hour flight, the pilot radioed air traffic controllers to say that he was returning to Heathrow.
BA confirmed: “The aircraft had to return due to several cabin crew feeling unwell.”
But the airline denied rumours that the jet had suffered from a faulty oxygen supply. However, there was no comment on whether the outbreak of illness could have been related to food.