The son of immigrants, Rene Nuñez was born in 1936 and raised in San Diego. He graduated from San Diego High School in 1955, and joined the army four years later. After leaving the army, Nuñez attended the University of California, Los Angeles where he received his Bachelor's degree in Spanish in 1967. During this time, he worked as the Director of the Educational Clearinghouse, a college outreach program for Chicano/a and African-American students living in LA's underprivileged neighborhoods. As an activist dedicated to improving Chicano education, Nuñez participated in the 1968 Chicano Student Walkouts, and helped to organize the Biltmore Hotel educational demonstration of 1968. He was arrested as part of the "Biltmore 10." He played a major role in the 1969 UC Santa Barbara Conference of Chicano students, professors, and activists. The conference discussed educational issues in the Chicano community, and resulted in the creation of "El Plan," a blueprint for the codification of Chicano Studies programs at the university level. Several universities implemented the plan the following year. The conference also established the Movimiento Estudiantil Chicano de Aztlán (MEChA). In addition to this work, Nuñez was active in the anti-war movement as well.

In 1969, Nuñez became Director of the Centro de Estudios Chicanos at SDSU. He formally joined the faculty in 1971, and helped to develop the curriculum for the Chicana and Chicano Studies department. In his classes, Nuñez promoted the principles of the Chicano Movement, celebrated Chicano history and culture, and encouraged community outreach and involvement. In 1972, Nuñez received a Master's degree in Urban Studies from Occidental College. In 1985, he obtained a Master's in Political Science from UCSD, and in 1994 he acquired a joint doctorate in education from SDSU and Claremont Graduate University.

In 2002, Nuñez retired as Professor Emeritus of Chicano Studies. He continued teaching and remained an active participant in the San Diego County Latino Coalition for Education, the National Association of Chicana and Chicano Studies (NACCS), the Latino Education Summit, and La Rama de Padres Latinos. Nuñez died in 2006. Faculty at SDSU held a "Teach-In and Call to Action" in honor of Nuñez.