Dan Adkins was born in West Virginia, in the basement of an unfinished house. He left the state "when I was about 7" as his family moved to Pennsylvania; Reno, Nevada; Phoenix, Arizona; New York; Ohio; and New Jersey. When he was "about 11" years old, Adkins said, he had a bout with rheumatic fever that left him paralyzed from the waist down for six months. Serving in the Air Force in the mid-1950s, stationed at Luke Field outside Phoenix, Adkins was a draftsman. As he described the job, Launched in 1956, that publication was Sata, filled with fantasy illustrations and reproduced on a spirit duplicator. In Phoenix, Arizona, Adkins met artist-writer Bill Pearson who signed on as Sata's co-editor. In 1959, Pearson became the sole editor of Sata, ending the 13-issue run with several offset-printed issues. Adkins contributed to numerous other fan publications, including Amra, Vega and Xero. At 19, Adkins began doing freelance illustration for science-fiction magazines. He moved to New York City at and when he was "about 24" years old was an art director for the Hearst Corporation's American Druggist and New Medical Material magazines. Ss he recalled:
In 1964, during the period comic-book fans and historians call the Silver Age of Comics, Adkins joined the Wally Wood Studio as Wood's assistant. Wood and Adkins collaborated on a series of stories for Warren Publishing's black-and-white horror-comics magazines Creepy and Eerie. Adkins was among the original artists of Wood's T.H.U.N.D.E.R. Agents, for Tower Comics, drawing many Dynamo stories during his 16 months in the Wood Studio. He joined Marvel Comics in 1967. working primarily as an inker but also penciling several stories for Doctor Strange and other titles. Adkins additionally worked for a variety of comics publishers, including Charlton Comics, DC Comics, Dell Comics/Western Publishing, Eclipse Comics, Harvey Comics, Marvel, and Pacific Comics. In addition to penciling and inking, Adkins also did cover paintings, including for Amazing Stories, Eerie and Famous Monsters of Filmland. His magazine illustrations were published in Argosy, Amazing Stories, Fantastic, Galaxy Science Fiction, Infinity, Monster Parade, Science-Fiction Adventures, Spectrum, Worlds of If and other magazines. In the 2000s, he illustrated Parker Brothers products, and his artwork for Xero was reprinted in the hardback The Best of Xero.