Lawrence W. Conant, 80, a retired government engineer and founder of the Dad-Coached Clubs of Washington, died Tuesday at Doctors Hospital of an aortic aneurysm.

Mr. Conant began working with the Army Corps of Engineers in the late 1930s. He then worked for the former Federal Aviation Agency from 1950 until his retirement in 1965.

Before that, he had worked in his grandfather's furniture business in New York state and as a researcher for the Brookings Institution here.

Mr. Conant was born in Paris, France. His mother died in childbirth and he was adopted by his maternal grandparents and reared in Camden, N.Y.

In 1921, he earned a bachelor's degree in engineering from the Massachusetts Institute of Technology.

After moving here in 1932, Mr. Conant began working with area youngsters. Before founding the Dad-Coached Clubs in 1935, he was a scoutmaster and boys' camp counselor and had organized a number of other athletic clubs for boys in the Cleveland Park area. Toward the mid-1950s, the clubs became supplanted by organizations such as the Little League.

Mr. Conant's work with the Dad-Coached Clubs was featured in a 1949 article in the Saturday Evening Post.

After his retirement from government, Mr. Conant began studying cybernetics. He belonged to the Society for General Systems Research, a cybernetics study and research group.

Mr. Conant was a member of Cleveland Park Congregational Church and of the MIT Alumni Association.

Survivors include his wife, Dorrit, of the home in Washington; two sons, William W., also of Washington, and Spicer V., of Phoenix, Ariz.; a daughter, Margaret C. (Peggy) Michael, of Louisville, Ky.; 13 grandchildren, and one great-grandson. A son, George F., died in 1976.

The family suggests that expressions of sympathy be in the form of contributions to the Renewal Fund of Cleveland Park Congregational Church.