Connor Barron, Kelle Roos and Anthony Stewart will all leave Aberdeen this summer but the Dons have signed defender Gavin Molloy and forward Peter Ambrose.
Junior Hoilett has also been offered a permanent deal and Aberdeen “remain in discussions” with the former QPR and Cardiff City winger, who joined on loan when Neil Warnock was in charge.
The Dons made several offers to try to persuade 21-year-old Barron – who has been linked with a move to Rangers – to stay at Pittodrie, but say the midfielder has “decided his future lies elsewhere”.
Molloy, a 22-year-old centre-back, has joined from League of Ireland Premier Division side Shelbourne on a three-year deal for an undisclosed fee.
The Dubliner made 79 appearances for Shelbourne and featured 22 times in the ongoing season.
Ambrose has joined from Hungarian side Ujpest for an undisclosed fee and has also signed a three-year deal.
The 22-year-old, who moved from his native Nigeria to start his career in Turkey in 2021 with Balikesirspor, finished last season as Ujpest’s top scorer with 10 goals from 27 starts.
“I’m delighted Peter has chosen to join us here at Aberdeen. He is very driven and ready to represent the Dons,” said new Dons boss Jimmy Thelin.
“Gavin has developed a growing reputation in Ireland. He brings great versatility, a positive attitude and is a leader, something which is important for a strong and successful team.”
Molloy believes Aberdeen is the perfect next step in his career.
He said: “It feels brilliant to officially be an Aberdeen player. As soon as I heard about the opportunity, I wanted to put the red shirt on.
“This is the right step in my career. The history, the size of the club, it was something I really wanted to be part of.
“I had a good conversation with the manager. He had done a lot of research on me and told me how I would fit in and he left a really positive impression.”
Following loans at Edinburgh City and Kelty Hearts, Barron made his Dons debut in January 2022 in a Scottish Cup win against Edinburgh City and became established as one of the Scottish game’s top midfielders.
Roos arrived at Pittodrie in the summer of 2022 and immediately established himself as the club’s number one goalkeeper.
He played 90 matches across all competitions, keeping 30 clean sheets.
Stewart was signed from Wycombe Wanderers that same summer and the defender was made club captain by Jim Goodwin for that season.
After 28 games he joined MK Dons on loan in January 2023 and has been at Stadium MK for the last 18 months.
The trio will join Jonny Hayes in their time with the Dons ending, with the winger confirming last week he was departing after playing more than 350 times.
Youngsters Kieran Ngwenya, Finlay Murray, Kai Watson, Chris Kondolo, Aaron Reid, and Reuben Smillie will also leave Pittodrie while on-loan Stefan Gartenmann of Midtjylland and Crystal Palace’s Killian Phillips have returned to their parent clubs.
Swede Thelin has finally started work as Aberdeen’s new manager following Warnock and Peter Leven’s spells in caretaker charge, saying it is an opportunity “to create something great” at Pittodrie.