The deal extends Pearson’s time at Deepdale to the end of the 2019/20 campaign and is a reward for the fine form he has shown in recent months.
The 21-year-old joined North End from Manchester United in January and had 18 months left on his current contract.
Pearson said: “It has been a good few months for me, a big learning curve with being out of the team and then getting back into it.
“I’m really happy to be here for another three-and-a-half years and I will continue to work hard and progress in that time.
“This is a good club to be at, the lads are a great bunch and I’m enjoying my football which is the main thing.”
North End manager Simon Grayson said: “Ben has been very good for us, especially this season.
“Last season was about finding his feet after coming into the club, we saw a lot of potential in him.
“The first part of this season he didn’t get into the team but he has shown character and determination to get back in and cement a place.
“He has been one of our best players over the last few months since getting back into the team.
“The reward of a new contract is fitting for him and vital to us to keep progressing as a football club.
“Ben know he cannot stand still, he has to keep improving day by day, game by game.
“It is something that we look to do with our younger players and better players, get them tied down here.”