The highly-anticipated Marvel movie sees the 47-year-old actor and Hugh Jackman, 55, reprise their respective superhero roles as the unlikely duo embark on a multiverse adventure.
Reynolds revealed he chose to change the movie's in February once online sleuths went ballistic after learning the film was called Deadpool and Friend.
During an appearance on Jimmy Kimmel Live - on which the movie stars filled in as guest co-hosts - Reynolds said: "I've never told this story anywhere, but the movie was originally called Deadpool and Friend. I am actually not joking.
"On the eve of the Super Bowl, the Super Bowl is where we first launched the trailer for Deadpool - not Friend, but Wolverine - it leaked because of the internet.
Ryan Reynolds and Hugh Jackman reprise their superhero roles in Deadpool and Wolverine. (AP PHOTO)
"The title leaked. We looked at it and listened, and they hated that title. We were not feeling so good about that any more."
Although he was adamant to amend the flick's name, Reynolds admitted it took a while to convince Marvel Studios to agree to the change.
"We were like, 'No, we're changing the title, I will never call this movie Deadpool and Friend.' And they did it, they did it. They really changed the title."
Even before the film's name leaked, Reynolds was determined to ensure more sensitive details about the movie didn't make its way online before hitting cinemas, and so planned to film a fake "intentionally bad" flick known as Alpha Cop to throw leakers off the scent.
"I even had one of the posters made. It was about two guys who are sharing one brain and together they make the ultimate cop. And the poster says, Alpha Cop: Two Cops, One Brain. All Balls," Reynolds said.
"It was meant to be kind of like horrible, so 10 people in America would go see this movie on opening weekend and five minutes into the movie, the Marvel logo would flip up and it would actually be Deadpool and Wolverine."
15°C