Larry Lieber is an American comic book writer and artist, born Lawrence D. Lieber on October 26, 1931, in New York City. He is best known for his extensive work at Marvel Comics, where he played a foundational role in the Silver Age of comic books. Lieber is the younger brother of the legendary writer, editor, and publisher Stan Lee.

Lieber's most significant contribution to popular culture is his work as a co-creator of several enduring Marvel superheroes. Working from plots by his brother Stan Lee, Lieber scripted the debut stories and early appearances of Thor in Journey into Mystery, Iron Man in Tales of Suspense, and Ant-Man in Tales to Astonish. This work included inventing the civilian names for these characters, such as Donald Blake for Thor and Tony Stark for Iron Man. Beyond these superhero origins, Lieber is also known for his long tenure writing and drawing the Marvel Western series Rawhide Kid from 1964 to 1973 and for illustrating the syndicated newspaper comic strip The Amazing Spider-Man from 1986 to 2018.

In the context of Japanese anime and manga, Lieber is not a direct creator but is consistently credited as an original creator due to his foundational work on the Marvel characters on which these productions are based. For the 2013 Japanese-American anime film Iron Man: Rise of Technovore, produced by Madhouse and Marvel Entertainment, Lieber is officially credited alongside Stan Lee, Don Heck, and Jack Kirby for the creation of the underlying Marvel comics characters. Similarly, for the manga Avengers: Zombies Assemble, published by Kodansha in 2015, Lieber is listed as an uncredited original creator for his co-creation of Iron Man. This pattern of recognition extends to other Marvel anime productions. He receives credit for his character creations in anime such as Marvel Anime: Iron Man, and the films Ultimate Avengers, The Invincible Iron Man, Hulk Vs, and Avengers Confidential: Black Widow & Punisher. This credit typically appears in the form of a "based on the Marvel comics by" or "original creator" attribution, acknowledging the character's source material rather than direct involvement in the Japanese adaptation.

Lieber's artistic identity is rooted in the Silver Age Marvel method, where he would script full stories from a plot provided by Stan Lee, which were then drawn by artists like Jack Kirby and Don Heck. His career has been defined by his versatility, moving between scripting superhero origins, writing and drawing Westerns, and illustrating daily newspaper strips. His recurring theme has been the development of flawed, relatable heroes, as seen in the origins of Tony Stark and Dr. Donald Blake.

Lieber's industry significance is profound, though often overshadowed by his more famous brother. He is the co-architect of three major pillars of the Marvel Universe: Iron Man, Thor, and Ant-Man. These characters have become central figures in global multimedia franchises, including the Marvel Cinematic Universe, and their presence in anime and manga adaptations directly stems from the foundational work Lieber did in the early 1960s. In recognition of his contributions, he received the Bill Finger Award in 2010. His role as a writer and artist helped define the narrative and visual language of Marvel Comics during its most formative period.