Eleanor Blewett Worthy, 56, a founder of the Chelsea School, which is for children with learning difficulties, and the first chairman of its board of directors, died of cancer Sunday at the Memorial Hospital of the Sloan-Kettering Cancer Center in New York City.

The Chelsea School was opened in 1976 in Bethesda and now is located in Silver Spring. Mrs. Worthy, who lived in Bethesda, was its chairman from 1976 to 1979 and remained a member of the board until her death.In 1979, the school's library was named after her.

For many years, Mrs. Worthy was active in the Junior League in Washington. She was the chairman of its Children's Theater and its Thrift Shop and a member of its volunteer service board. She also was a founder and twice was the chairman of the Antiques Group, an organization for women interested in antiques.

She was a member of the Women's Board of the Columbia Hospital for Women.

Mrs. Worthy was born in Newport News, Va. She moved to the Washington area after World War II.

Survivors include her husband K. Martin Worthy, of Bethesda and "Tardree," the family's country home in Sparta, N.J.; a daughter, Jeffrie, of Silver Spring; a son, William, of Bethesda, and two sisters, Mrs. Sidney A. Sherwin Jr. of Batavia, N.Y., and Mrs. Marshall Simonds of Carlisle, Pa.

The family suggests that expressions of sympathy be in the form of contributions to Memorial Hospital, Sloan-Kettering Cancer Center, New York City, or to the Chelsea School Scholarship Fund in Silver Spring.