Roald H. Fryxell (February 18, 1934–May 18, 1974) was an American geologist and archaeologist.
Roald Hilding Fryxell was the son of Fritiof Fryxell, a geologist and professor, and Regina Holmén Fryxell, an organist and music teacher, both on the faculty of Augustana College in Illinois, from which he graduated in 1956 with a degree in geology.
Dr. Fryxell, known as "Fryx" by his friends, later became professor of geochronology at Washington State University. He was noted for his interdisciplinary work in geoarchaeology. During the 1960s Fryxell worked with two members of the U.S. Geological Survey under a National Science Foundation grant to study a site named Hueyátlaco, at the north shore of the Valsequillo Reservoir, in the state of Puebla, Mexico. They discovered stone tools that they dated from 250,000 years ago. This finding was received with great skepticism by the archaeological community.
In 1968 Fryxell was a co-principal investigator with Richard Daugherty (WSU) during the unearthing of the Marmes Rockshelter from the floodplain of the Palouse River near the confluence of the Palouse and Snake Rivers in southeastern Washington. The site was found to contain some of the oldest human remains in the western hemisphere at 12,000 years of age.
In 1971 he was selected to be part of the team of geologists in Houston who examined rocks brought back from the Moon during the Apollo program. He was also the designer of the apparatus used for collecting core samples of the moon's surface. The lunar crater Fryxell is named after him.
Fryxell died in 1974 in a car accident, and his family chose to honor his memory by endowing the Fryxell Award for Interdisciplinary Research, given annually by the Society for American Archeology in recognition of interdisciplinary excellence by a scientist. The SAA also holds a Fryxell Symposium during their meetings. An overlook shelter at the Palouse Falls is also named after him, as is the Roald H. Fryxell Memorial Scholarship at Augustana College.