The 31 year old's previous deal expired after the draw with Shrewsbury and manager Brian Laws is delighted to have finally wrapped up the deal.
“Karl’s been a very, very good player for us", he said.
“People might look and say he hasn’t scored a great deal of goals but he has contributed with goals and also had a big contribution with assists as well.
“He’s been a good player for us and we’re delighted we’ve agreed terms with him".
Hawley has scored five goals in 21 starts this season.