The 19-year-old has made one first-team appearance for Leeds this season.
“It’s a great club to be at and it was an easy decision as soon as it was put to me,” said Cairns.
“Making my debut is the highlight so far. Obviously the circumstances weren’t very good, but it was my debut and a chance to show the Leeds fans a little bit of what I can do.
“When you look at the chances the younger players have had this year, it proves the faith the manager Simon Grayson has in youth and shows that the club has a great Academy.
“I want to keep learning what I can and gain as much experience as I can. You have to bide your time as a goalkeeper and build your experience up before you get thrown in there.
“Hopefully I can do that and prove to the Leeds fans and the manager and coaching staff what I can do.”
