Joseph F. Fallon, 54, a Dominican priest for almost 25 years and then an editor of "The New Catholic Encyclopedia," died at his home in Columbia, Md., Saturday after a heart attack.

Mr. Fallon was ordained a Dominican priest in 1947. He left the priesthood in 1972 following a career in which he had taught at the Ecole Biblique in Jerusalem, at the Dominican House of Studies in Washington, at Catholic University and at Trinity College.

He was a specialist in Biblical literature and was an authority on the Dead Sea Scrools. He continued teaching after leaving the prieshood and taking an editorship with the Catholic encyclopedia.

Mr. Fallon was born at Elmhurst, N.Y., and grew up in New York City. He graduated from Providence College, Providence, RI., and studied in Jerusalem and at the Angelicum in Rome. He was assigned to the Dominican House of Studies in Washington in 1956.

Survivors include his wife, the former Mary Gilbert, of the home in Columbia; his mother, Mrs. Thomas L. Fallon, of Park Ridge, Ill.; two sisters, Mrs. Robert Vinopal, also of Park Ridge, and Mrs. Mary Kattus, of Los Angeles, and two brothers, the Rev. Thomas L. Fallon O. P., of Providence, R.I., and John Jerome Fallon, of Los Angeles.