Born in Sacramento, California, to a first-generation Portuguese-Azorean immigrant family, he gained his popularity as part of the pop art movement of the 1960s. Ramos is “best known for his paintings of superheroes and voluptuous female nudes emerging from cornstalks or Chiquita bananas, popping up from candy wrappers or lounging in martini glasses”. He was also a university art professor.

Ramos attended Sacramento Junior College and San Jose State College. One of his earliest art teachers was Wayne Thiebaud, who is considered his mentor, and who remained his friend. Ramos received his B.A. and his M.A. from Sacramento State College, finishing his education in 1958. From 1958–1966, Ramos taught art at Elk Grove High School and Mira Loma High School in Sacramento. After two brief college teaching assignments, he began a long career (1966–1997) at California State University, East Bay, in Hayward, California, and then served as Professor Emeritus. He was Artist in Residence at Syracuse University and the University of Wisconsin.

Ramos married Leta (Helmers) Ramos in 1955, who was the model for many of his early nude paintings.

Ramos died of heart failure on October 14, 2018 at Kaiser Hospital in Oakland, California.

Ramos received his first important recognition in the early 1960s; since 1959 he has participated in more than 150 solo and 120 group shows.

Along with Roy Lichtenstein and Andy Warhol, he was one of the first artists to do paintings of images from comic books, and works of the three were exhibited together at the Los Angeles County Museum of Art in 1963. Along with Claes Oldenburg, James Rosenquist, Tom Wesselmann and Wayne Thiebaud, Ramos produced art works that celebrated aspects of popular culture as represented in mass media. His paintings have been shown in major exhibitions of pop art in the U.S. and in Europe, and reproduced in books, catalogs, and periodicals throughout the world.

In 1986 he received a National Endowment for the Arts Visual Artists Fellowship Grant.

In 2009, Ramos was part of the first Portuguese American bilingual art book and exhibit in California “Ashes to Life a Portuguese American Story in Art” with fellow artists Nathan Oliveira, John Mattos and João de Brito.

Ramos originally showed with Leo Castelli. Then Ivan Karp introduced Ramos’ work to the art dealer Louis Meisel. He was represented by the Louis K. Meisel Gallery since 1971. He has also been represented for many years by San Francisco’s Modernism gallery, Galerie Ernst Hilger, Austria and Burkhard Eikelmann Gallery (Düsseldorf).

A major exhibition of his work was held at the Albertina in Vienna in 2011.

A retrospective of over 50 years of his work opened at the Crocker Art Museum in his hometown of Sacramento on June 2, 2012. This show is “the first major exhibition of his work in his hometown”, and his first American retrospective in 35 years.

His work can be found in the permanent collections of the New York Museum of Modern Art, Solomon R. Guggenheim Museum, and Whitney Museum of American Art, the San Francisco Museum of Modern Art, the Norton Simon Museum, and the Hirshhorn Museum in Washington, DC.

According to the Artnet Price Database, Ramos’s £1.07 million [$1.69 million] auction record was set at Sotheby’s London in 2012