Rosemary Tharp was born on January 26, 1921, in Cedar Falls, Iowa. She entered Iowa State Teachers College (now the University of Northern Iowa) in 1938 and graduated in 1942. After working a summer making cartridge belts for the army at the Hinson Manufacturing Company in Waterloo, Iowa, she began teaching junior and senior high school social studies in Kanawha, Iowa.

In December 1942, Tharp joined the WAVES, the women's branch of the Navy. She was sent first to Smith College and later to Mount Holyoke College, both in Massachusetts, for officer's training and communication school. After training, Tharp was assigned to a naval air station in Minneapolis, Minnesota. Later she became head of the communications department there; however, since women were not supposed to have men under their charge, a male personnel officer held the position on paper.

In 1944, she married Herman Tharp, whom she had been dating since college. She was discharged from the WAVES on October 25, 1945. Tharp later returned to school to earn a master's degree. She worked in the Department of Otolaryngology and Maxillofacial Surgery at the University of Iowa Hospitals, Iowa City, and helped to author several scientific articles during the early 1970s. From 1977 until her retirement in 1985, she was employed as a research assistant in the Department of Preventive Medicine, State Cancer Registry of Iowa. She died of a stroke on September 27, 1994.