Foden scored on his final Northampton appearance back in May, signing off in style against Worcester Warriors at Franklin's Gardens.
It was a fitting finale for the full-back, who racked up 250 appearances in Saints colours, scoring 59 tries in the process.
Foden was a key man in the 2013/14 double-winning season and starred in Saints' run to the Heineken Cup final in 2010/2011.
The 33-year-old spent 10 seasons at Franklin's Gardens, earning a testimonial year, and he also won 34 caps for England.
And now he is looking forward to a fresh start in New York.
“I’m excited to announce that I’ll be joining MLR next season with Rugby United New York,” Foden said.
“It’s a new franchise in the most exciting city in the world.
"After my experience playing in the Premiership for 14 seasons, the opportunity to broaden horizons, in both a playing sense, as well as taking a step into the coaching role, seems like the right move.
"I fully believe America to be the next big rugby playing nation and can’t wait to help develop young talent through the professional ranks.
"My family and I have always wanted to venture across the pond to America, and now have the opportunity, which we look forward to seizing with both hands.”
Rugby United New York is a professional rugby team who joined Major League Rugby as an associate member in 2018, playing a brief, but successful exhibition season.
Their first full MLR schedule will take place in 2019.
And Rugby United New York general manager James English said: “We’re absolutely delighted Ben has signed for us.
“As one of the most influential and talented full-backs in the Premiership over the last decade, the opportunity of signing him was too good to turn down.
"Ben brings a wealth of Premiership and international experience to Rugby United New York.
"His signing is a real statement of intent by the club.
"We’re looking forward to the impact he can have on the field, culturally, and off the field, aiding in the development of young talent in the tristate area.
"We look forward to welcoming Ben to New York.”