England manager Thomas Tuchel is set to confirm his 26-man group, but Maguire has already been informed that he will not travel to the tournament. The decision came as a major surprise to the Manchester United defender, who believed his recent performances had earned him a place.
"I was confident I could have played a major part this summer for my country after the season I've had," Maguire said.
"I've been left shocked and gutted by the decision. I wish the players all the best."
The 33-year-old had rebuilt his standing at Manchester United during the campaign and recently agreed a new contract after an impressive turnaround under manager Michael Carrick.
However, Maguire's omission comes while legal issues connected to his 2020 arrest in Greece continue to follow him. Earlier this year, prosecutors linked to the case argued that Maguire should not represent England at the World Cup after he received a suspended 15-month sentence following a retrial in Syros.
Maguire was found guilty of non-serious assault, resisting arrest and attempted bribery. The defender has strongly denied wrongdoing, labelled the case "a shambles" and plans to appeal the ruling.
Meanwhile, Levi Colwill is reportedly in contention for a place despite an injury-hit season with Chelsea. The 23-year-old centre-back was included in Tuchel's extended shortlist after returning from an ACL problem.
Maguire has earned 66 caps for England and played at three major tournaments. He was a key figure during England's run to the semi-finals at the 2018 World Cup and also featured heavily in Qatar four years later.
But his international opportunities have become limited since Euro 2024. He featured only briefly during Tuchel's first matches in charge, including appearances against Uruguay national football team and Japan national football team earlier this year.
Now, one of England's most experienced defenders will watch the 2026 World Cup from home after Tuchel made one of the boldest selection calls of his reign so far.