DelHoyo, who was raised also in Salt Lake City, Utah, began performing in the theatre in New York City during the 1970s. Working under the name George Deloy, he performed in plays and musicals at many of the major American regional theaters such as The Seattle Repertory, The American Conservatory Theatre in San Francisco, The Old Globe in San Diego, The Cincinnati Playhouse, The Mark Taper Forum in Los Angeles & The Huntington Theatre in Boston. His first big break came in 1976, playing Kyle Nunnery in the Broadway Musical, The Robber Bridegroom.
DelHoyo has gained notoriety as a top voiceover artist, lending his voice to numerous Hollywood film trailers and network television promos. In 2008 he was featured in the acclaimed book "Secrets Of Voice-Over Success" by Joan Baker.