The contract will reportedly earn the 23-year-old £150,000-a-week, making him the highest-earning defender at the club and one of the world's best paid defenders.
The news brings to an end a year of speculation about Shaw's future at the club, following a rumoured falling-out with manager Jose Mourinho. The Portuguese coach frequently questioned Shaw's form last year and directly criticised the former Southampton youngster's fitness during the summer
.However, the full-back has started the season in fine form and has reportedly been rewarded with this huge new deal, which also helps United avoid the embarrassment of the player leaving for a cut-price over the next year or on a free transfer at the end of his contract.
Shaw signed for United in 2014 from Southampton for an undisclosed fee, believed to be in the region of £30 million - making him the most expensive teenager in world football at the time.
The England international broke his leg at the start of his second season at United, suffering a double fracture in the Champions League group game against P