Matheny was born in Los Angeles, California. Matheny was in the United States Air Corps during World War II. He was shot down while flying over Germany in January 1944, and spent over a year as a prisoner at Stalag 17-B near Krems, Austria.  After the war he was a mechanic for Western Air Lines and then joined the military again to serve in the Korean War. By the time he began his studies at BYU he was a 32-year-old freshman with a wife and four children.
He earned his BA and Master's degrees at Brigham Young University in 1960 and 1962, and a PhD degree in anthropology from the University of Oregon in 1968. He was involved in many archaeological expeditions to Mayan cities. He was closely connected with the New World Archaeology Foundation.
Matheny was also involved in archaeological studies of the Southwestern United States, Utah, Great Basin, and Bronze Age Israel. He directed archaeology field schools in Montezuma Canyon and Nine Mile Canyon, Utah. He edited a volume on the rock art of the inter-mountain region of the United States.
Matheny was also closely connected with the establishment of the BYU Field School in Southern Utah. The University of Utah press published a collection of essays in his honor, written by colleges, many his former students, which focused heavily on south-west US and Meso-American archeology.
- "Ray Thomas Matheny". The Salt Lake Tribune. Retrieved 16 July 2020.
- article about Matheny's military career
- BYU-New World Archaeological Foundation
- BYU Museum of Peoples and Cultures publication list
- BYU Magazine, Summer 2001
- BYU Magazine, Spring 2000
- description of book published in Matheny's honor
- Matheny obituary