We won't give away his appearance in the movie (trust us, it's great), but he did reveal that it won't be his last Marvel movie.
"I've since done a cameo for 'Ant-Man,'" he excitedly told Business Insider.
The next film to come out from Marvel Studios on July 17 stars Paul Rudd as Scott Lang, who is armed with a super suit that gives him the ability to shrink in scale but increase in strength.
"It was the most difficult movie to work on because everyone has to be careful where they're stepping because they might accidentally crush the leading man," Lee said jokingly. "But seriously, 'Ant Man' is going to be great. It's going to be different than any other superhero movie and the fans are going to love it."Lee didn't give us any more details about his cameo in "Ant-Man," only promising us, "it's great!"