Striker Ricky Jade-Jones was confirmed on Thursday May 20, after centre-back Ronnie Edwards penned a new deal on Tuesday.
Both 18-year-olds are now on four-year contracts, much to the delight of manager Darren Ferguson.
It was also announced that 25-year-old Frankie Kent had signed a contract that will keep him at the club until 2024.
Jones, who was born in Peterborough, joined Posh as a nine-year-old and has progressed through the academy to first-team football at the Weston Homes Stadium, already making 33 senior appearances and netting his first league goal on the final day of the 2020/21 season at Doncaster Rovers.
He was involved in 19 games overall in the 2020/21 campaign, although he missed the first part of the season after suffering an injury in a pre-season friendly against Coventry City and only returned in January.
Manager Darren Ferguson was pleased to secure Jones' long-term future after reports that the academy striker was attracting interest from top clubs.
He said: "Ricky has developed nicely over the last couple of years. The boy has massive potential.
"You can see the improvement in his performance against Doncaster, his hold-up play was very good, as was his movement.
"We know he has that pace that frightens defenders, he gets you up the pitch, he presses, and he has good energy, he needs to improve in certain areas, but I thought his performance at Doncaster was the best he has done in terms of playing against two experienced centre halves and causing them so many problems.
"He has been involved in pretty much all of the squads when he has been fit and available for selection.
"He has had one or two injuries to contend with but he is someone that I am excited to work with and I am delighted we have managed to tie him down on a longer deal."
Jones commented: "I believe I am in the right place to continue my development. The manager has been first class with me.
"The staff have looked after me and I am really looking forward to returning after the summer break a Championship player, but I will be pushing hard for a place in the first team.
"I don’t want to just settle for being on the bench, I want to fight for a position.
"To have come through the Academy system and be in the position I am now, signing a long-term professional contract, is a great feeling, and it is really nice that myself and Harrison Burrows have been on that same journey."
Frankie Kent was equally thrilled about the offer of a three-year contract to stay with Peterborough, describing it as a "very easy decision to make".
He added: " I have loved every minute of my time at the club. Getting promotion just topped that off and I couldn’t think of anywhere better to be than here at this moment in time."
The 25-year-old missed just one game as Peterborough secured automatic promotion this season, prompting praise from his manager.
Ferguson said: "Frankie has been a brilliant signing for us. He has been very consistent, he has definitely improved, he comes in, gets on with his work, enjoys it, knows he is at the right club for him, and I believe he can kick on again.
"He can go under the radar and I think that is because he is so consistent, you just expect an 8/10 from him every game that he plays.
"He still has things to learn, but he has done very well in whatever system we have played. I have no worries about Frankie coping in the Championship."
Meanwhile, Tuesday's signing to secure Ronnie Edwards was described as "a big one" for Ferguson, the Posh co-owners and Barry Fry, director of football.
Ferguson told the Posh website: "I am delighted. Ronnie has caught everyone’s attention with the calmness and maturity in which he plays.
"He has suffered some injuries which has been a hiccup for him and a real shame for the lad, because he would have featured a lot more.
"He is a big one for us because we see real potential in the boy. Thankfully, we have managed to get it done and get it done quickly and I am looking forward to continuing working with him next season."
Edwards made his second league appearance earlier this month as Peterborough celebrated promotion to the Sky Bet Championship with a season-ending 4-1 win at Doncaster.
He said: "I believe I am in the right place for my development. The manager has been brilliant with me, he gives young players an opportunity and I am looking forward to coming back in pre-season fit and raring to go.
"When I got the opportunity to play this season, I wanted to show what I can do and show the manager what I can do.
"It was difficult picking up the injury so soon after the enforced break for Covid-19 over Christmas. I worked hard to get back fit before the end of the season and it was great to be involved on the final day against Doncaster."
Last week, Posh revealed that six players were being released, while four were available for transfer.