Roger Lee Reynolds (born July 18, 1934) is an American composer. He is known for his capacity to integrate diverse ideas and resources, and for the seamless blending of traditional musical sounds with those newly enabled by technology. Beyond composition, his contributions to musical life include mentorship, algorithmic design, engagement with psychoacoustics, writing books and articles, and festival organization.

During his early career, Reynolds worked in Europe and Asia, returning to the US in 1969 to accept an appointment in the music department at the University of California, San Diego. His leadership there established it as a state of the art facility – in parallel with Stanford, IRCAM, and MIT – a center for composition and computer music exploration. Reynolds won early recognition with Fulbright, Guggenheim, National Endowment for the Arts, and National Institute of Arts and Letters awards. In 1989, he was awarded the Pulitzer Prize for a string orchestra composition, Whispers Out of Time, an extended work responding to John Ashbery’s ambitious Self-Portrait in a Convex Mirror. Reynolds is principal or co-author of five books and numerous journal articles and book chapters. In 2009 he was appointed University Professor, the first artist so honored by University of California. The Library of Congress established a Special Collection of his work in 1998.

His nearly 150 compositions to date are published exclusively by the C. F. Peters Corporation, and several dozen CDs and DVDs of his work have been commercially released in the US and Europe. Performances by the Philadelphia, San Francisco, Los Angeles, and San Diego Symphonies, among others, preceded the most recent large-scale work, george WASHINGTON, written in honor of America's first president. This work knits together the Reynolds's career-long interest in orchestra, text, extended musical forms, intermedia, and computer spatialization of sound.

Reynolds's work embodies an American artistic idealism reflecting the influence of Varèse and Cage, as well as Xenakis, and has also been compared with that of Boulez and Scelsi. Reynolds lives with his partner of 59 years, Karen, in Del Mar, California, overlooking the Pacific.