Manchester United announced the deal to keep Lingard at Old Trafford through 2021 and noted the contract came with an option for a fifth year.
Jim White of TalkSport reported the deal is believed to be worth £100,000 per week.
Having emerged from the United youth setup, Lingard enjoyed a breakthrough season in 2015-16 under the guidance of former manager Louis van Gaal.
The winger's versatility and industry in the final third made him a useful option to have in the squad, as did Lingard's ability to chip in with some key goals. The 24-year-old's campaign culminated in a memorable winner in the final of the FA Cup against Crystal Palace.
Having spent time away from Old Trafford on loan with the likes of Birmingham City and Derby County, there have been doubts as to whether Lingard could make it at Old Trafford. But this long-term contract is a huge show of faith in the player.
Indeed, football journalist Musa Okwonga noted earlier in the campaign that he feels as though Lingard can follow a similar path to Pedro at Barcelona:
There are certainly similarities. Lingard, like the current Chelsea man, is a willing worker and will run himself into the ground for the sake of the team. As an academy graduate, the 24-year-old is also well attuned to the ethos of the club and what the fans demand from their players.
Improvements need to be made, though. Lingard has brilliant pace, great energy and a penchant for netting vital goals, but overall his decision-making can be erratic when under pressure, while there are times where he looks a little too hesitant with the ball at his feet.
As noted by sports journalist Liam Canning, in United's loss to rivals Manchester City earlier in the campaign, Lingard looked a long way short of the quality required to make an impression:
Manager Jose Mourinho will feel as though Lingard still possesses malleable attributes and, as such, can make strong progress under his guidance. If the winger wants to feature regularly, it's imperative that process continues.
After all, with Anthony Martial, Marcus Rashford, Henrikh Mkhitaryan and Juan Mata all able to operate in similar positions, Lingard needs to do something special to stand out at Old Trafford. This new deal suggests the belief is there that he can do so.