Smith, 32, has represented her country 90 times, scoring 16 goals and manager John Buckley is delighted Smith has agreed to join the club at the third time of asking.
"Signing Sue is a tremendous coup for the club," he said. "She is probably the most famous player in England and a very experienced international.
“We’ve tried to bring her to the club in the past but it didn’t quite happen. But I’m delighted that we have managed to get a deal done this time round.
“Sue will be instrumental in shaping our future both on and off the field with her extensive experience.
"It is very exciting for the town especially as Sue will be visiting schools and clubs in the region on our behalf inspiring young females to follow in her footsteps."
Smith a former International Player Of The Year started her career with Tranmere Rovers before joining Leeds United in the summer of 2002. She enjoyed a successful time at Leeds including winning the 2010 FA Women’s Premier League Cup before moving to Lincoln for the FA WSL in 2011.
Belles' manager Buckley "Sue is an exciting player who has great quality on the ball and is capable of creating and scoring goals for the club. She is a key signing for us as we look to add more quality to improve the squad moving in to the second FA WSL campaign.
"We have a very young and exciting squad and Sue will add some much needed experience for the forthcoming campaign. "
She Kicks - the online news service for women's football