John J. McCarthy, 73, a retired consultant and former Senate aide who was an official of the Small Busines Administration during the Eisenhower administration, died Sunday at a hospital in Sante, Fe, N.M., of Parkinson's disease complicated by pneumonia.

Mr. McCarthy and his wife, Viola, lived in Colorado Springs, Colo., for nearly two years before moving to Sante Fe in May to be near a daughter, Mary Stetten.They lived in Alexandria for 29 years before that. d

In the 1930s and 1940s, Mr. McCarthy was an aide to two senators from Minnesota, the late Elmer J. Ryan, a Democrat, and the late Edward J. Thye, a Republican.

During World War II, he was a lieutenant commander with the Navy's Bureau of Personnel here.

When the SBA was established in 1953, Mr. McCarthy was appointed assistant to the administrator by President Eisenhower, a position he held until 1961, when Eisenhower left office.

He then was a consultant to the government and private industry before retiring in the early 1970s for reasons of health.

Mr. McCarthy was born in Montgomery, Minn., and graduated from the College of St. Thomas in St. Paul. He also attended the universities of Minnesota and Colorado. He was a high school principal in Minnesota before moving to this area.

Besides his wife and daughter, of Sante Fe, survivors include another daughter, Cathy Van Hartesveldt of San Rafael, Calif., a son, John P., of Colorado Springs; a brother, Francis of Boston, and four grandchildren.