The carrier, which plans to offer 22 flights per day from the London airport to the US by summer 2022, marked the arrival of its first flight into Heathrow on Friday (15 April).
United employees and crew joined Bob Schumacher, director of sales UK and Ireland, to welcome United Flight 24 from Boston.
The new service will be operated with Boeing 767-300 aircraft, which feature a total of 167 seats – 46 flat-bed seats in business class, 22 United Premium Plus seats and 99 in economy.
Schumacher said: "We are excited about our all-new service between London Heathrow and Boston, which provides our customers in the UK with even greater travel choice and direct access to Boston and the broader New England region.
"This is a wonderful area of the United States and truly has something for everyone. We very much look forward to welcoming our customers on board this new service."
