Catherine Grigsby Mayo, 81, a retired French teacher in the D.C. Public Schools who was active in civic and community organizations, died of cardiac arrest Oct. 11 at Howard University Hospital.

Her civic activity had ranged from being a founder and president of the Trinidad Citizens Association in the 1940s to serving on the board of directors of the Near Northeast Community Improvement Corporation (CIC), an antipoverty program agency serving northeast Washington, in the ate 1970s.

Mrs. Mayo also had been a member of the board of the D.C. League of Women Voters, a founder of the Mt. Olivet Heights Civic Association, and had been active in travel and historical groups. She was a member of the Lincoln Memorial Temple of the United Church of Christ.

She taught French in District of Columbia high schools for 30 years before retiring in 1965. She was on the faculty at Cardozo High School from 1935 to 1960, then taught at Eastern High School from 1960 to 1965.

Mrs. Mayo was a native of Montclair, N.J., and had lived in Washington since 1935. She was a graduate of Smith College and earned a master's degree from Teachers College at Columbia University. She also studied in France at the University of Paris. Before coming to Washington, Mrs. Mayo taught French at Talladega College in Alabama, and at Virginia State College.

Her husband, Charles Mayo, died in 1950. Mrs. Mayo's survivors include two sisters, Pearl Richardson of Montclair, N.J., and Marian Thompson of Columbia, S.C.