The 32-year-old moved to the Saints from Sale Sharks in 2008 and helped the club win the European Challenge Cup in 2009 before losing out to Leinster in the final of the Heineken Cup in 2011.
However, Foden became the first player to score in consecutive Premiership finals in 2013 and 2014 against Leicester Tigers and Saracens respectively as the Saints claimed successive titles.
Foden made 22 appearances at fullback in the 2013-14 season as the Saints added the European Challenge Cup to their Premiership crown.
He has also played 34 times for England, scoring seven tries, including two during the 2011 Rugby World Cup.
Foden is set to lead the side out for his 250th and final appearance in a Saints shirt when they host Worcester Warriors on Saturday.
He told the club's website: "I'm honoured to have had the opportunity to represent Northampton Saints almost 250 times.
"I've enjoyed some incredible highs at this club over the last 10 years, winning trophies both in this country and across Europe. I want to thank all of the team-mates and coaches that I have worked with in that time, as well as wishing everyone that is staying here all the best for the future.
"I'm also so grateful to the club's supporters, who have been behind me right from the beginning and made me feel loved every time I ran out at Franklin's Gardens, and I leave with memories of them that I will cherish forever.
"I still feel fit and hungry for competitive rugby, and while now is the time to move on, I am really excited for what the next chapter holds in store for me."
Interim head coach Alan Dickens added: 'Fodes has been a remarkable player for both Northampton Saints and England.
"We'll miss having him around Franklin's Gardens, both in terms of what he offers on the pitch as a player and a leader, but also as a character in the dressing room."