Long was loaned out to Portsmouth earlier in the season and has since played five times for the Clarets since his return to Turf Moor.
The Irishman, who signed from Cork City in January 2010, has agreed a deal which also includes the option of a further year at the end of the initial spell.
"I'm delighted to have signed. I have enjoyed my time here and particularly since I have managed to get into the team in recent weeks," he told the club's official website.
"I had a lot to learn when I came but I have benefitted from all the loan moves I have had and it's been great to have had the chance now to play for Burnley. It's what I wanted.
"I just plan to keep doing the best I can and I am looking forward to the future here now."
Long is yet to finish on the winning side for Sean Dyche's side but he is confident that will soon change.
"From a personal point of view I am delighted to be in the team and playing games, but we are not picking up results so it's disappointing," added the 22-year-old.
"But I think bar the Huddersfield game the other night (a 1-0 home defeat) we have played well and if we play like we did against Middlesbrough and Brighton we will start picking up points again."