Rixey Smith, 89, retired administrative assistant to the late senator Carter Glass (D-Va.) and a member of an old Virginia family, died of cardiac arrest Thursday at his home in St. Augustine, Fla., where he had lived since 1973.

He was born John W. Rixey Smith in Rixeyville, Va., but dropped his first name as a young man. He attended the University of Virginia and graduated in 1915 from the College of William and Mary, where he was elected to Phi Beta Kappa.

Mr. Smith served in France with the Army Singal Corps in World War I and suffered an impairment of his hearing. After the war, he worked as a Washington correspondent for the Baltimore Sun, until Sen. Glass hired him as his secretary in the early 1920's.

Later, Mr. Smith became his administrative assistant. He remained with Sen. Glass until the latter's death in 1946. During that time he had published a biography of his employer.

In the late 1940's, Mr. Smith, worked on the technical staff of the Bureau of Internal Revenue. He also was president of the Woodlawn Foundation, establsihed to preserve the historic mansion that was the gift of George Washington to Nellie Custis.

A resident of Great Falls, Va., for many years, he moved to Leesburg. There he lived until moving to Florida.

His wife, Grace Bagge Quinten Smith, died about 25 years ago.

He is survived by a sister, Genevieve Scott, of Waynesboro, Va.