The departures of Paul Doran Jones (Harlequins), Ryan Lamb (Leicester), Brian Mujati (Racing Metro), Martin Roberts (Bath), Mark Sorenson (Bristol) and Soane Tonga'uiha (Racing Metro) have already been announced.
The Saints can now also confirm that Scott Armstrong, Tom May and Rhys Oakley (player/coach at Plymouth Albion) are also leaving the club.
Director of rugby Jim Mallinder said that all of the players had made a big impression at Franklin's Gardens.
"If a team is to succeed every player in the squad has to contribute," he commented. "Everyone in the squad has done this during the season, whether playing for the first or second teams, in training or in analysis and team meetings.
"On behalf of the rest of the coaching team I'd like to thank the players who are leaving for what they've done in their time at the Saints, and wish them the best for the future."