Liam has a lot of potential, with good pace and a lot of skill." said Cobblers boss Stuart Gray.
"I am sure we can help get the best out of him and he is a player with the hunger and desire to do well.
"He can play on the wing or at full back and gives us options down the left hand side, very much like Daniel Jones did last season. "He has what you are looking for in a young player; as well as being full of energy, he has a powerful shot, good technical ability and he has a good build.
"We have always said that our recruitment this summer will be a mix of young players with potential and experienced players.
"Liam will be a good addition to the squad and our work to strengthen further is still ongoing."