Muriel Gill Webb Thompson, 68, a Washington artist and a former president of the Ladies' Board and trustee of the House of Mercy, died of cancer Feb. 21 at the Washington Hospital Center.

Mrs. Thompson, who lived in Chevy Chase, was born at "Gills View," her family's property in Dinwiddie County, Va. She grew up in Washington, where she graduated from the old Western High School. She also graduated from Columbus University law school, which is now part of Catholic University. From 1938 to 1942, she worked for the Federal Reserve Board.

As an artist, Mrs. Thompson worked in pastels and oils. She painted landscapes, still-lifes and portraits. She won prizes at local shows, including some in the Maryland State Women's Clubs competitions.

Mrs. Thompson was a member of the Washington Cathedral Association and active in the Cathedral Flower Mart. She was a member of the Garden Club of Chevy Chase, the Sulgrave Club and the Chevy Chase Club, where she helped organize a tennis program for youngsters in the 1960s. She taught tennis at the Holton-Arms School.

Survivors include her husband, John W. Thompson Jr., a former vice president of The Washington Star newspaper and president of the Washington Star Broadcasting Companies, of Chevy Chase; three children, Anthony John, of Barnesville, Md., Muriel Elizabeth Thompson Young of Narragansett, R.I., and Joan Webb Thompson Secrest of Bethesda; two sisters, Jacqueline W. Young of Potomac and Dorothy W. Reudiger of Washington, and seven grandchildren.