The new board of directors includes chairman Henrik Kraft, Dragan Solak and Rasmus Ankersen, while incoming director of football Jason Wilcox, formerly of Manchester City, begins his role in July.
Further changes include the appointment of Darren Mowbray as head of recruitment, replacing Joe Shields who left the Saints in October to join Chelsea after just four months at St Mary's, while Mark Bitcon has joined as director of performance.
Southampton's first task is to appoint a new head coach to replace Ruben Selles, with Swansea City boss Russell Martin reportedly on the verge of taking the reins for the Saints' return to the Championship.
The future of a number of star players will also need to be resolved quickly, none more so than captain James Ward-Prowse, who is expected to bid an emotional farewell to his boyhood club as he seeks to continue his career in the Premier League.
Southampton may also struggle to keep hold of Romeo Lavia, who has attracted interest from a number of top Premier League clubs, while Armel Bella-Kotchap has been tipped to return to his native Germany amid reported interest from Eintracht Frankfurt.
The likes of Che Adams, Carlos Alcaraz, Kyle Walker-Peters and Mohammed Salisu may also depart this summer if top-tier clubs come calling.
Meanwhile, Theo Walcott has already confirmed that he will leave St Mary's in the summer upon the expiration of his contract, and the same is set to apply to both Mohamed Elyounoussi and Willy Caballero.
The number of outgoings will likely determine how many new signings are brought into the club this summer, although some of the club's highly-rated academy graduates such as Dom Ballard, Kami Doyle and Sam Amo-Ameyaw could be given an opportunity to step up to the first team.
After two disappointing transfer windows in the first full season of Sport Republic's majority ownership, Southampton can ill-afford another year of poor recruitment, and, as simple as it sounds, incoming players need to have greater quality that those currently at the club if they are to challenge for an immediate return to the top flight.
Recruiting players to match the philosophy of the incoming manager is imperative and the addition of a proven goalscorer will be high on the agenda, while upgrades in defence and a new creative midfielder to fill the void set to be vacated by Ward-Prowse should also be targeted.