Ryan Reynolds has paid an emotional tribute to a young fan who died after a battle with cancer.

Paying tribute to his "great friend", Ryan wrote on Facebook: "For three straight years, my friend, Connor McGrath drop-kicked cancer... Not sure how... Maybe the cancer cheated... But the fight came to an end two nights ago.

"Connor was 13. But this kid... He was smart. He was funny. And not just funny 'for a kid' - or funny 'for a person battling something awful'. He was unqualified funny. He had that... thing.

"That thing you see in great performers or comedy writers. A running commentary/observational skill people are just lucky to be born with.

"He went way too early and it's impossible to reconcile. Connor was a great friend, a great son, and a light to the people lucky enough to know him. While repeatedly punching cancer in the balls, he made everyone laugh. Including the entire staff who cared for him at Edmonton's Stollery Children's Hospital."

Ryan also revealed that Connor was the first person to see 'Deadpool' after he surprised him with a rough cut of the movie before its release and Ryan, 39, believes his late friend embodied all of the best parts of the hilarious comic book character.

In the post - which included some pictures of him and Connor - he said: "Connor was the first person to see Deadpool. I traveled up to Edmonton, Alberta to surprise him with a rough cut of the film.

"***Before you jump down my throat for showing a 13 year old an R-Rated film, please know this kid knew more swear words than a British chef.

"I'm grateful I got to orbit Connor's world for a brief time. Grateful for the pages and pages of hilarious texts between us. Grateful to his parents for allowing Connor to spend time with a foul-mouthed child in the body of a 39 year old.

"I called Connor, "Bubba". And he called me "Bubba2". We met because he loved Deadpool. In a certain sense he WAS Deadpool. Or, at least everything Deadpool aspires to be; balancing pain, fearlessness, love and a filthy (filthy!) sense of humor in one body. I wish he could've stuck around a lot longer (sic)."

And Ryan - whose wife Blake Lively is expecting the couple's second child - encouraged others to make a donation to the The Make-A-Wish Foundation.

He added: "If you'd like to donate to The Make-A-Wish Foundation, I can pretty much guarantee, your money's going to a damn good place. These people do not suck. They are heroic. Full stop. makeawishna.ca/wishes/donate."