Reynolds, who plays the superhero Deadpool, shared a photo of the comic book writer on Instagram.
“Thanks for everything, Stan,” the actor wrote next to the image.
Jackman, who has played Wolverine in the X-Men movies as well as in solo films, posted a photo of himself with Lee on social media.
“We’ve lost a creative genius,” Jackman wrote. “Stan Lee was a pioneering force in the superhero universe.
“I’m proud to have been a small part of his legacy and… to have helped bring one of his characters to life.”
Kat Dennings, who took on the role of Darcy Lewis in the Thor franchise, also shared an homage to Lee.
She posted a photo of herself with the Marvel boss and called him “the legend of legends”.
“Thank you, Stan Lee. It was an honour to be a small part of your universe,” she added.
Chris Evans, also known as Captain America, posted his tribute on Twitter.
“There will never be another Stan Lee,” he wrote.
“For decades he provided both young and old with adventure, escape, comfort, confidence, inspiration, strength, friendship and joy.
“He exuded love and kindness and will leave an indelible mark on so, so, so many lives.”
Evans ended his tribute with “Excelsior!” in reference to the catchphrase famously used by Lee.
Patton Oswalt, who played several Koenig brothers in the Agents of S.H.I.E.L.D. TV series, said Lee deserved a “permanent cameo in heaven”.
He was referencing the many appearances Lee made in Marvel movies, regularly popping up to the delight of fans.
J August Richards, who appears as Michael Peterson and Deathlok in Agents of S.H.I.E.L.D., posted a photo of himself with Lee.
“You’re going to see a lot of these today because he touched so many of our lives and was incredibly gracious in person,” he wrote in reference to the Marvel co-creator.
“Thank you Stan Lee for allowing me to dream as a child then realise my dream as an adult…”
While Seth Rogen has never been involved in a Marvel film, he sill shared a message to honour Lee’s memory, writing: “Thank you Stan Lee for making people who feel different realise they are special.”