Edna Rees Williams was born on June 25, 1899 to Arthur and Rose (Longmire) Williams. Edna grew up in Tallahassee, Florida and attended Florida State College for Women (now Florida State University), where she received her B.A. in 1920. She later received both her M.A. and Ph.D. degrees in English from Yale University in 1929 and 1936 respectively.

In 1930 Williams joined the Smith College English Department as Instructor. In addition to teaching general courses, she gave courses in the field of medieval literature, such as Old English (Beowulf), Chaucer, and the History of the English Language. At various points she taught classes at Mount Holyoke College, the University of Massachusetts, and the University of London. She rose through the ranks of the department steadily and was appointed Professor of English in 1959. In the academic year 1960-61 she was awarded a grant as a Fulbright Lecturer in English to teach at Japan Women's University in Tokyo. In many ways this was the culmination of Williams' longtime interest in foreign education. In addition to acting as a guide and mentor to the many foreign students who studied at Smith each year, she had also served for several years as chairman of the Committee on Foreign Students at Smith. She often formed close relationships with these students and it was common for her to keep in touch with them for years after their graduation. In 1964, Williams officially retired and was named Professor Emeritus of English Language and Literature by the Trustees, but continued to teach a reduced class load. In 1982-83 Williams was named a Sophia Smith Fellow.

Williams' major published work is The Conflict of Homonyms in English, a development of her Ph.D. thesis, published in 1944. She also authored several articles for scholarly journals and a few short reviews.

Williams died on May 28, 1992, at the age of 92 in Tallahassee. She had lived in Northampton until 1991.