The 18-year-old is joining Villa following a successful trial, the club confirmed on Monday afternoon.
Mason, 18, linked up with Villa in April ahead of his Southampton contract expiring and went on to start all six of the Under-21 side’s remaining fixtures, scoring in the 3-2 win at Middlesbrough.
Featuring at both centre-back and in a defensive midfield role, the versatile teenager will now continue his footballing education in the Midlands after the coaching staff were impressed enough with his performances to offer him professional terms.
Having also been on the books of Spanish giants Real Madrid and Blackburn Rovers during his short but nomadic career, the Lancashire-native possess a great deal of potential and Villa manager Tim Sherwood could just be the ideal coach to help him fulfil it.
Mason is not the lone youngster committing his future to the claret and blues, though, with scholars Charlie Bannister, Rory Hale, Harry McKirdy Anes Omerovic, Joonas Sundman and Moustafa Zeidan all confirmed to be signing their first professional contracts with the club.
In addition, Under-21 prospects Riccardo Calder, Henry Cowans, Lewis Kinsella, Tom Leggett, Jerrell Sellars, Benjamin Siegrist, Ben Swift, Brad Watkins and Josh Webb are all penning contract extensions, while Liam Bateman is set to sign a month-to-month deal.
Along with Mason, the likes of Calder and Kinsella, who both featured on the senior bench last season, are worth keeping close tabs on moving forward, while Swiss goalkeeper Siegrist could well have a first-team future at Villa Park if he can recover from the broken leg sustained last month.