The 38-year-old, who is South Africa’s most capped player, will link up with his new team-mates after completing Rugby World Cup duties.
Matfield was linked with Saints in 2008, with reports suggesting that he would join from Toulon on a £325,000-a-year contract.
But the move never came to fruition and he opted to return home, where he has been a stalwart for the Bulls in Super Rugby.
He won the title three times as captain, adding the same number of Currie Cups to his personal medal haul.
But he will now finally make the switch to Franklin’s Gardens, bolstering Saints’ second row options for the new season.
“Victor is one of the outstanding forwards in world rugby,” Mallinder said.
“He has been at the top of the game for well over a decade now and his selection by South Africa for a fourth consecutive World Cup shows that he remains a force to be reckoned with.
“We’re very much looking forward to Victor joining up with the squad and believe he has a lot to offer the club, not only on the field, but also off it in terms of his leadership qualities and experience.”
And Matfield can’t wait to test himself in the Aviva Premiership.
He said: “It is an honour for me to join the Northampton Saints.
“Seven years ago Saints very nearly became my rugby home and I feel privileged to be given another opportunity to join the club.
“I join Saints to make the best contribution I possibly can and I have a genuine desire to hopefully play an instrumental role in a team effort, with the aim of lifting silverware in both the Aviva Premiership and the European Rugby Champions Cup.
“For now I will focus only on the Springboks’ campaign to win the Rugby World Cup but I am very excited about the journey with Saints from November onwards.”