The fast food giant is offering its “McDelivery” service through UberEats, with orders available from 22 locations across the capital and another 10 restaurants in Leeds and Nottingham.
It comes after similar tie-ups with Uber in the US, while McDonald’s already delivers in China and Singapore.
Customers will be able to order food through the UberEats app, which then uses Uber couriers to deliver the food.
McDelivery is available on breakfast, lunch and dinner menus from 7am to 2am, although customers must live within 1.5 miles of restaurants in the trial.
Claude Abi-Gerges, a McDonald’s franchisee who owns and operates five of the London restaurants taking part in the trial, said the service would bring customers a “new level of convenience”.
“It’s the next chapter in how we get freshly made, great-tasting food to our customers in a way that suits them and fits around their busy lives,” he added.
McDonald’s said restaurant teams would be monitoring the trial closely to see what worked and what did not.
Mathieu Proust, general manager of UberEats, said: “We’re excited to be working with McDonald’s to begin delivery of their food for the first time in the UK.
“Our technology means people can get the food they want with the speed and reliability they’ve come to expect from Uber.”
The launch comes after KFC launched home deliveries across 30 restaurants in Greater London via the Just Eat platform earlier this year.
Recent figures show home deliveries of ready-to-eat food grew 10 times faster than the eating out market last year.
The delivery sector jumped almost 10% to 599 million visits in Britain last year, while total visits out to restaurants and other dining venues rose by just 1%, according to analysts NPD Group.