The pair have been key men for the Premier League side this season.
Southampton have reported on their official website that goalkeeper Fraser Forster has signed a new five-year deal at St Mary's, while the club's website also confirmed that midfielder James Ward Prowse has agreed a six-year extension with the Saints.
The pair have been important members of Ronald Koeman's squad over the past two seasons, and have now followed in the footsteps of Virgil van Dijk by committing their long-term future to the club.
And Forster suggested that the centre-back's extension was one of the factors that persuaded him to extend his stay on the south coast.
"If you look at just last week with Virgil signing his new deal, that was obviously positive news and after last year and then this year it's obvious things are moving forward and hopefully we can keep doing that in the future," he told the club's official website.
Meanwhile, Ward Prowse - who came through the academy at Southampton - admitted that there was no decision to make once he found out that the club were hopeful of agreeing fresh terms.
"I'm delighted. When I knew I had the chance to extend my stay here it was a no-brainer for me," he also explained to the club's website.
"It's pleasing that the club have shown that they have faith in me to extend my stay and I want to repay the faith to the club for putting their time and effort into making me the player I am today."
Though the midfielder has struggled to hold down a regular spot in the first-team - having started in just 14 of his 32 league appearances for the side this term - it is obvious that he is one of the brightest talents that is currently pushing for a place at the club.
Meanwhile, although Forster spent a large part of the season out injured, his return has highlighted just how much the Saints have missed him. He kept six clean sheets in his first six games back in the side, and his performances since then have helped keep the team in Europa League contention going into the final day of the campaign.