Larson was born and raised in University Place, Washington in suburban Tacoma to Verner, a car salesman, and Doris, a secretary. He graduated from Curtis Senior High School in University Place and from Washington State University in Pullman with a degree in communications. During high school and college, he performed jazz on guitar and banjo.
Larson acknowledges his family has ’a morbid sense of humor’ and he credits his older brother, Dan, for his ‘paranoid’ sense of humor. Dan pulled countless pranks on Gary, taking advantage of his fear of monsters under the bed by waiting in the closet for the right moment to pounce. Dan ’scared the hell out of me’ whenever he could, Gary has said, but Dan is also credited for nurturing Gary's love of scientific knowledge. They caught animals and placed them in terrariums in the basement, even making a small desert ecosystem.
According to Larson in his anthology ‘The Prehistory of the Far Side’, he was working in a music store when he took a few days off, after finally realizing how much he hated his job. During that time, he decided to try cartooning. In 1976, he drew six cartoons and submitted them to Pacific Search (afterwards Pacific Northwest Magazine), a Seattle-based magazine. After contributing to another local Seattle paper, in 1979 Larson submitted his work to The Seattle Times. Under the title ‘Nature's Way’ his work was published weekly next to the Junior Jumble.
To supplement his income, Larson worked for the Humane Society as a cruelty investigator. Larson decided he could increase his income from cartooning by selling his strip to another newspaper. While on vacation in San Francisco, Larson pitched his work to the San Francisco Chronicle. To Larson’s surprise, the Chronicle bought the strip and promoted it for syndication, renaming it ‘The Far Side’. A week later, The Seattle Times dropped ’Nature’s Way’.
Since retiring from The Far Side, Larson has done occasional cartoon work including magazine illustrations and promotional artwork for ‘Far Side’ merchandise. In 1998, Larson published his first post-Far Side book, ‘There's a Hair in My Dirt! A Worm's Story’, an illustrated book in the Far Side mindset.
After Larson’s success with the San Francisco Chronicle, ‘The Far Side’ was syndicated in 1980 by Chronicle Features. Its first appearance was in the Chronicle was on January 1, 1980. It ran for fifteen years until Larson retired, with his final strip published on January 1, 1995. Larson thought the series was getting repetitive and did not want to enter what he called the ’Graveyard of Mediocre Cartoons’.
Themes in The Far Side were often surreal, such as ‘How cows behave when no human watches’ or ‘The unexpected dangers of being an insect’. Often, the behavior of supposedly superior humans was compared with animals, surrounded by fences and dense housing. A father explains to his son that a bird song is a territorial marking common to the lower animals. Animals and other creatures were frequently presented anthropomorphically. For example, one strip depicts a family of spiders driving in a car with a ’Have a Nice Day’ bumper sticker, featuring a ‘smiley face’ with eight eyes.
One of Larson's more famous cartoons shows a chimpanzee
Larson's ’Far Side’ cartoons were syndicated worldwide and published in many collections. They were reproduced extensively on greeting cards, which were very popular; however, they were discontinued in March 2009. Two animated versions were produced for television, Tales from the Far Side (1994) and Tales from the Far Side II (1997).