Victor Moscoso is a Spanish–American artist best known for producing psychedelic rock posters, advertisements, and underground comix in San Francisco during the 1960s and 1970s. He was the first of the rock poster artists of the 1960s era with formal academic training and experience. He was the first of the rock poster artists to use photographic collage in many of his posters.

Moscoso was born in the Vilaboa parish of Culleredo, Galicia. He moved with his mother to Oleiros. His father, whose parents had already emigrated to New Jersey, exiled to the U.S. after being persecuted by the falange. At the age of four, Moscoso and his mother, joined his father, and travelled to Brooklyn, where he stayed until he was an adult. His father worked as a painter and taught him about color combination. His mother was a seamstress

After studying art at Cooper Union in New York City and at Yale University, Moscoso moved to San Francisco in 1959. There, he attended the San Francisco Art Institute, where he eventually became an instructor.

Moscoso's use of vibrating colors was influenced by painter Josef Albers, one of his teachers at Yale.

Professional success came in the form of the psychedelic rock and roll poster art created for San Francisco and Denver’s dance halls and clubs. Moscoso's posters for the Family Dog dance-concerts at the Avalon Ballroom and his Neon Rose posters for the Matrix resulted in international attention during the 1967 Summer of Love. From September to December 1967 his psychedelic posters done for Chet Helms’ Family Dog Denver further extended his accomplishments and recognition. Moscoso's poster work includes album covers for musicians such as Jerry Garcia, Bob Weir, Herbie Hancock, Jed Davis, and David Grisman.

By 1968, Moscoso was doing work for underground comix, for such titles as Yellow Dog, Jiz Comics, Snatch Comics, El Perfecto Comics, and Zap Comix. As one of the Zap artists, his psychedelic work once again received international attention. His comics appeared in every issue of Zap from 1968 until the title's final issue in 2014; he also illustrated the covers for Zap #s 4, 10, and 13. Moscoso's comix work is notable for its repetitive framing and reliance on an eight-panel grid. The subjects of his comics in Zap are often classic characters like Mickey Mouse, Donald Duck, Krazy Kat, Mr. Peanut, Bugs Bunny and Winsor McCay's Little Nemo.

In 1977, Moscoso designed radio station KMEL's mascot: a camel wearing headphones. (The station used the KMEL call letters to name itself "Kamel 106".)

Moscoso has also created art for use on T-shirts, billboards and animated commercials for radio stations, for which he received two Clio awards. In addition, he was given an Inkpot Award in 1979. Moscoso was a 2018 AIGA Medalist.

In 1979, the French publisher Futuropolis published Moscoso Comix #1, a 52-page collection (which was republished in English 1989). Sex, Rock 'N' Roll, & Optical Illusions, a comprehensive collection of Moscoso's poster and comics work, was published by Fantagraphics in 2006, featuring introductions by Steven Heller and Milton Glaser.

Moscoso returned to Galicia for the first time in 1965, at age 29. In 2016, he described the visit as "Travelling a 100 years back in time. I was able to visit my grandparents who were, at the time, very old." Even though he returned sporadically after that, he showed interest in visiting again, as the last time he did so was in 2001. As of 2021, Moscoso still lives in the San Francisco Bay Area.