McGill spent the first half of last season on loan at MK Dons, starting 25 games, but was recalled in January after the loan agreement was terminated. The Canadian international has signed a two-year deal as he attempts to compete for a place in the first team against Jason Steele and Bart Verbruggen.
Seagulls manager Fabian Hurzeler praised the 25 year old and revealed that he cannot wait to see what the future holds for the shot stopper.
“Tom has been an important part of our goalkeeping team for a long time, and we’re pleased to see that continue.
“He gained some valuable experience with MK Dons this season and we’re confident that Tom will continue to improve with us.”
Another Brighton prodigy Carl Rushworth is also pushing for a place in first team alongside McGill after loan spells at Swansea and Hull City and could rival him in the years to come.