Hammill is keen to help Barnsley win promotion to the Premier League this season.
“I just want to continue playing well for Barnsley,” explained Hammill. “I enjoy my football here and the fans are great with me.
“This club is ambitious. Burnley and Blackpool have shown what you can do with good players and some good team spirit – and we’ve got both here.
“If we can get up there to the top end of the table by Christmas, then who knows what we can achieve?”