The group flew from Santa Barbara airport to watch the popstar perform one of her last residencies at Resorts World Theatre, with Celine Dion later spotted in the same VIP area with the Sussexes.
It is approximately 359 miles between Santa Barbara and Las Vegas, with a drive taking five or six hours compared to a one hour 15 minute flight.
Harry and Meghan have previously been blasted for continuing to use their private jet to fly to exotic destinations all over the world, in spite of their protestations about fighting climate change.
In September the couple were revealed to have taken seven international flights over the space of just two weeks, with critics claiming they should “practise what they preach”.
In 2019 Harry spoke to Vogue magazine about his environmental concerns, stating: “We are the one species on this planet that seems to think that this place belongs to us, and only us.”
On September 7 Harry flew from LA to London for the WellChild Awards, then travelled onto Germany the next day for the Invictus Games, with Meghan joining him a few days later on two separate flights.
Once the Games wrapped the pair travelled to Portugal for a short holiday, before returning home to LA once again via Heathrow on September 20.
Then in October the Duke and Duchess flew privately to the exclusive Caribbean island of Canouan for a mini-break following an engagement in New York, returning home via Atlanta, Georgia.
In 2021 the Sussexes pledged on their Archewell site that they would be carbon-neutral by 2030, and Harry has also previously said they would only have two children due to their carbon footprint.
Royal commentator Richard Fitzwilliams has said that while taking flights is sometimes unavoidable, the couple need to take care to avoid accusations of hypocrisy.
He told Express.co.uk: “If you preach about climate change, as Harry and Meghan do, you should, where possible, practise what you preach.”
“On the one hand, the Sussexes champion saving the planet but when they take private jets, they must expect to be criticised. Surely a private jet to fly to Las Vegas was unnecessary.
“On this occasion what happens in Vegas doesn’t stay in Vegas but is shared by the world. Harry will recall his earlier experience there with mortification. This is surely hypocritical!”