McCarthy was born in Salt Lake City, Utah, and studied art at the University of Utah and Weber State University in 1969. He went on to study at the San Francisco Art Institute receiving a BFA in painting. In 1972 he studied film, video, and art at the University of Southern California receiving an MFA. From 1982 to 2002 he taught performance, video, installation, and performance art history at the University of California, Los Angeles. McCarthy currently works mainly in video and sculpture.