James Ward-Prowse, Lloyd Isgrove, Jordan Turnbull and Jack Stephens have all signed new contracts during the past 12 months.
Highly-rated left-back Luke Shaw has also recently agreed a new deal and 18-year-old Chambers has now followed suit.
With the club since the age of seven, the England Under-19s international become an impressive right-back after starting in midfield.
Chambers has been heavily involved during pre-season and is now targeting a regular first-team berth.
"It's fantastic - it's like my dream, really," he told the club's official website, www.saintsfc.co.uk.
"I've been at the club since I was so young, so this is a great feeling. I've been here since I was seven and I've been treated really well so it means the world.
"The club has a great set-up and it's going through a really good time at the moment. There are going to be big things from Southampton in the future.
"I've always wanted to play for the first team at this club, and this is another step towards that."
Source: PA
Source: PA