Dora White Spencer, 69, a longtime resident of Washington who was active in school, church and service organizations, died Thursday at the Washington Hospital Center. She had cancer.

Mrs. Spencer was born in Providence, R.I. She moved to Washington in 1922 when her step-father, Richard S. Aldrich, was elected to Congress. She graduated from the Holton Arms School here and later attended Smith College.

In 1935, she married Samuel Spencer, an attorney who served as president of the D.C. Board of Commissioners in the 1950s. The couple moved to Washington, where Mrs. Spencer entered a private law practice.

Except for some years during World War II, when she returned to Providence to live with her family while her husband was serving in the Navy in the Pacific. Mrs. Spencer spent the rest of her life in Washington.

She was a former trustee and chairman of the board of the Potomac School. For several years she was a volunteer with the Head Start Program at St. Phillip's Chapel in Washington. Until earlier this year, she was secretary of the Women's Auxiliary Board of the Eastern Branch of the Boys Clubs of Greater Washington. She also was a member of the Sulgrave Club.

Mrs. Spencer also was a member of St. John's Episcopal Church, Lafayette Square, and was the first woman to serve on its vestry.

Survivors include her husband, of Washington, three children, Henry Benning Spencer, of New York City, Janet Spencer Dougherty, of Wayne, Pa., and Richard A. Spencer, of Portland, Me.; one sister, Janet Barnes, of New Haven, Conn.; one half brother, Richard S. Aldrich, of Providence, R.I.; 10 grandchildren and one great-grandchild.