William T. Fryer, 80, professor-emeritus of the George Washinton University law school, died of pneumonia Friday at his home in Bethesda.

Prof. Fryer was born in Colora, Md., in Cecil County. He served in the Marine Corps in World War I and then came to Washington as a student at the Georgetown University School of Foreign Service. He graduated from George Washington University in 1922 and earned his law degree there in 1924. In the following year, he earned a doctorate in law at Yale University.

After a year in a private practice in Baltimore, Prof. Fryer began his teaching career at George Washington. His subjects were evidence, personal property, public utilities and legal methods and legal systems. This last was a first-year course designed to introduce students to how the law and the courts work and how they have developed.

Prof. Fryer was the author of several textbooks, including "Selected Readings on Evidence and Trial," which was published in 1957, and "Readings on the Study of Law and the Anglo-American Legal System," which he wrote with Prof. C. D. Benson and which was published in 1937. Prof. Fryer also wrote "Cases and Materials on Legal Method and Legal Systems," which was published in separate editions in 1949 and 1950.

During World War Ii, Prof. Fryer was on leave from GW to serve as a lieutenant colonel in the office of the Marine Corps Judge Advocate General.

He retired from George Washington in 1965 and was named professor-emeritus on that occasion. He taught at the school for an additional year and later was a visiting professor at Washington & Lee University, the University of Arkansas, Hastings University in San Francisco, and the University of Baltimore.

Prof. Fryer was a member of the Bethesda Presbyerian Church and the Edgemoor Civic Association, to which he contributed legal advice. He also was a member of Phi Delta Phi, a legal fraternity.

Survivors include his wife, Betty, whom he married in 1932, of Bethesda; a daughter, Mary Doerfer, of Shellmare, Ecuador; a son, William T. Iii, of Vermillion, S.D.; two sisters, Violette Lincoln and Mrs. A. F. DeCourtenay, both of Upper Montclair, N.J., and six grandchildren.