William P. Kelly Jr., a former official with the War on Poverty during the Johnson administration and a federal employe for 22 years, died of a heart attack May 11 at Suburban Hospital in Bethesda.

Mr. Kelly, who lived in Annandale, was born in Pittsfield, Mass. During World War II, he served in the Army in Europe. He graduated from Ohio State University in 1951, and his federal service began that year when he went to work as a clerk with the Army in Columbus, Ohio. He came to Washington in 1959 and joined the National Aeronautics and Space Administration as director of the procurement and logistics branch.

Later, he was an official in the Peace Corps and the Agency for International Development. He joined the War on Poverty in 1964 as the director of management and administration in the Office of Economic Opportunities. He served as director of the Job Corps in 1967, then left federal service to work for Volt Information Sciences Inc. and the Kennedy Institute.

In 1977, Mr. Kelly was assistant executive director for operations of President Carter's reorganization project. He later served as commissioner of the federal supply service of the General Services Administration. He retired in 1979. Mr. Kelly then taught at Northern Virginia Community College until last fall.

Survivors include his wife, the former Rossie Drummond, of Annandale; and six daughters, Mary Hjelm of Falls Church, Kathleen, of Springfield, Ruthann and Eileen, of Annandale, Sheila, of Alexandria, and Margaret, of Radford, Va., and four grandchildren.