Riley Hughes, 66, a retired associate professor of English at Georgetown University who was an author and critic, died Sunday at Sibley Memorial Hospital after a heart attack.

Mr. Hughes, who retired last year, taught English at Georgetown for 34 years. He also taught courses in journalism. In 1960, he helped found the annual Georgetown University writers conference and had served as its director.

He had been a contributor to the Catholic Standard, the Saturday Review and Commonweal magazines. He reviewed fiction for the Catholic World. For the past 20 years he had written a monthly book review column for "Columbia," the publication of the Knights of Columbus.

He was the author of several novels, including "The Hills Were Liars" and "Frontier Bishop," both published in the 1950s. He also had written short stories, poems and two books on writing.

Mr. Hughes, who was born in New Haven, Conn., had been a resident of Washington since 1946. He was a graduate of Providence University and earned a master's degree in English at Brown University.

He was a member of St. Ann's Catholic Church in Washington and of P.E.N., the international writers' organization.

Survivors include his wife, the former Josephine Nicholls, of Washington; two sons, Austin L., of Westover, W. Va.; and Dennis D., of Columbus, Ohio; two daughters, Winifred Spar of Princeton, N.J.; and Hildred Crill of Chapel Hill, N.C., and two grandchildren.