Clarkson J. Beall, 80, one of the principal developers of the Beaufort Park subdivision in Fulton, Md., died Sunday at the Lorien Nursing Home in Columbia. He had cancer.

Mr. Beall, who was born in Toronto, Canada, graduated from the College of Agriculture of the University of Maryland in 1918. He then returned to Canada and served in the Canadian Army in the closing months of World War I. Subsequently, he travelled widely, living in Canada, France and elsewhere in Europe, and in New York City. During World War II, he was named chief of the North African division of the American Food and Agriculture Mission.

He made his permanent residence in this area in the late 1940s and became a realtor in Washington and Maryland. His major project over the years was the building of the Beaufort development in Fulton, where he lived. He remained active in the business until his death.

Mr. Beall was a member of the General Society of the War of 1812. He also was a founder of the Center of International Security Studies of the American Security Council Education Foundation.

Survivors include his wife, Denise, of Fulton.

The family suggests that expressions of sympathy be in the form of contributions to Mother Theresa, Calcutta, India, or to the Wurmbrand Foundation, P.O. Box 11, Glendale, Calif., 91209.