Jacob Allison Leapley, 89, a retired general contractor, died Wednesday at Providence Hospital. He had cancer and a heart ailment.

Mr. Leapley was born in Washington and went into the building trades as a young man. He served in the Army in World War I and also attended National University Law School.

In the early 1920s, he founded the J. A. Leapley Co., a contracting firm that specialized in renovations and later did custom home building in Washington and Montgomery and Prince George's counties. At one time, Mr. Leapley also headed a painting company.

He retired in 1977 for reasons of health. The company he founded is headed now by one of his sons, William E. Leapley Sr.

Mr. Leapley was a member of the parish of St. Mary's Catholic Church in Landover Hills and of the Rosensteel Council of the Knights of Columbus in Silver Spring. Until recently, he maintained a summer residence at Fairhaven, Md.

Mr. Leapley's wife, the former Helen Margaret McProuty, died in 1978.

In addition to his son William, of the home in Lanham, survivors include three other sons, Francis M., of Lanham, Joseph A., of Lothian, Md., and Robert A., of Clearwater, Fla.; three daughters, Helen L. Miele and Rita L. Clark, both of Silver Spring, and Mary L. King of Alexandria; 29 grandchildren, and nine great-grandchildren.