"Happy birthday to the legend," Ruffalo, who portrays the Hulk, said alongside a throwback, black and white photo of Lee standing in front of a shelf of comic books.
The one and only! Happy birthday!! https://t.co/Xh4XxYx0Eb— Chris Evans (@ChrisEvans) December 28, 2017
Kevin Feige, the president of Marvel studios, also wished Lee a happy birthday and teased that more cameos featuring the comic book icon appearing in various Marvel films are on the way.
"Happy 95th birthday @TheRealStanLee!!! #SoManyMoreCameosToCome," Feige said.
Lee last had a cameo in Marvel's Thor: Ragnarok, where he portrayed a hairdresser tasked with cutting Chris Hemsworth's (Thor) hair.
Lee, a former chairman of Marvel Comics, is known for writing and co-creating Marvel's staple of iconic superheroes including the Fantastic Four, the Hulk, Thor, Iron Man and the X-Men with Jack Kirby, and Spider-Man and Doctor Strange with Steve Ditko, among others.