In the TV-movie The Trial of the Incredible Hulk (1989), Lee's first appearance in a Marvel movie or TV project is as jury foreman in the trial of Dr. Bruce Banner.

In X-Men (2000), Lee appears as a vendor of a hotdog stand on the beach when Senator Kelly emerges naked onshore after escaping from Magneto.

In Spider-Man (2002), he appeared during Spider-Man's first battle with the Green Goblin, pulling a little girl away from falling debris.

In Daredevil (2003), as a child, Matt Murdock stops Lee from crossing the street and getting hit by a bus.

In Hulk (2003), he appears walking alongside former TV-series Hulk Lou Ferrigno in an early scene, both as security guards at Bruce Banner's lab. It was his first speaking role in a film based on one of his characters.

In Spider-Man 2 (2004), Lee again pulls an innocent person away from danger during Spider-Man's first battle with Doctor Octopus. He is later seen a second time, walking through the background when Peter is heading to class after giving up being Spider-Man.

In Fantastic Four (2005), Lee appears for the first time as a character from the comics, in a role credited as Willie Lumpkin, the mail carrier who greets the Fantastic Four as they enter the Baxter Building.

In X-Men: The Last Stand (2006), Lee and Chris Claremont appear as two of Jean Grey's neighbors in the opening scenes set 20 years ago. Lee, credited as "Waterhose man," is watering the lawn when Jean telekinetically redirects the water from the hose into the air.

In Spider-Man 3 (2007), Lee appears in a credited role as "Man in Times Square". He stands next to Peter Parker, both of them reading a news bulletin, and commenting to Peter that, "You know, I guess one person can make a difference". He then says his catch phrase, "'Nuff said."

In Fantastic Four: Rise of the Silver Surfer (2007), Lee appears as himself at Reed Richards' and Susan Storm's first wedding, being turned away by a security guard for not being on the guest list. In Fantastic Four Annual #3 (1965), in which the couple married, Lee and Jack Kirby are similarly turned away.

In Iron Man (2008), Lee (credited as "Himself") appears at a gala cavorting with three blond women, where Tony Stark mistakes him for Hugh Hefner.[71] In the theatrical release of the film, Stark simply greets Lee as "Hef" and moves on without seeing Lee's face; another version of the scene was filmed where Stark realizes his mistake, but Lee graciously responds, "That's okay, I get this all the time."[72]

In The Incredible Hulk (2008), Lee appears as a hapless citizen who accidentally ingests a soft drink mixed with Bruce Banner's blood, leading to the discovery of Dr. Banner's location in a bottling plant in Brazil.

In Iron Man 2 (2010), during the Stark Expo, Lee, wearing suspenders and a red shirt and black and purple tie, is greeted by Tony Stark as "Larry King".

Lee said he has met with Kenneth Branagh, director of the planned film Thor about his possible cameo in that movie and at Fan Expo 2010 Lee admitted to playing a truck driver in the film.[73]