The 32-year-old spent last season on loan at the Sanchez-Pizjuan and will continue to defend Sevilla's goal for the 2026-27 campaign after building a career across several of Europe's top leagues.
The Greece international was decisive in another difficult campaign for the Andalusians, making a string of key saves that helped secure survival.
Vlachodimos, with a deal at Newcastle United to 2027, made his debut with a win at Mendizorroza and went on to play 34 matches last season, conceding 53 goals.
"I've got two more years left on my contract with Newcastle, and all I can say now is I'm very happy here," Vlachodimos said in an interview with MARCA.
Other clubs had shown interest in the goalkeeper, but his clear wish to stay at Sevilla proved decisive in the negotiations.
Sporting director Jose Ignacio Navarro secured the loan renewal just days before the start of pre-season. Sevilla's first training session is set for 6 July, with medical examinations to take place the weekend before.
Coach Luis Garcia Plaza will therefore have his starting goalkeeper available from the very beginning of preparations for next season.
Sevilla's goalkeeping situation was further in the spotlight after Sergio Rico became a free agent on Wednesday.
The 32-year-old, who is from Sevilla, is available following the expiry of his contract with Qatari club Al-Gharafa, and has offered himself to his boyhood club.
"I'd love to go back to Sevilla, it would be like going home, somewhere I've spent even more time than in my own house," Rico said on the La Grada podcast.
"They helped shape me because I spent so much time at the training ground, and I still feel good, I feel 100% strong and I'd love to help the team in any way I can from the goal. It would be a real pleasure to go back to the club of my heart. The nicest and most special thing about a return to Sevilla this time would be having my children watching me from the stands."
Rico's comments leave the door open for a sentimental reunion, even with Vlachodimos already confirmed as the club's first-choice goalkeeper heading into the new campaign.
For now, Sevilla's immediate priority is settled, with Vlachodimos in place to lead the goalkeeping department as Garcia Plaza begins building his squad for 2026-27.