Joseph Quinton Conroy, 65, a retired chief of the communications management branch in the Office of Secretary of Transportation, died Monday at his home in Adelphi following a heart attack.

Mr. Conroy was born at Barrow-in-Furness, Lancashire, England. His family moved to the United States in 1922 and he grew up in Brooklyn. He graduated from the Pratt Institute there and became an artist and photographer.

During World War II, he was a medical illustrator and photographer in the Army Medical Services Corps. He served in the Philippines and elsewhere in the Pacific and then was assigned to the Armed Forces Institute of Pathology at Walter Reed Army Hospital here. He left the service in 1948 with the rank of captain.

Mr. Conroy continued to work for the Armed Forces Institute of Pathology at Walter Reed as a civilian. He later worked for the Amry Signal Corps.

In the late 1960s, he transferred to the Federal Aviation Administration, a part of the Department of Transportation. At the time of his retirement from the Office of the Secretary, he received a Distinguished Career Service plaque.

Mr. Conroy continued to paint throughtout his career. For the past nine years, he had taught watercolors and oil painting at Catholic University. He exhibited his work in art shows. His other interests included photography, travel and astronomy.

He was a member of St. Mark's Catholic Church in Adelphi.

Mr. Conroy's survivors include his wife, Helen, of the home; three daughters, Marilyn C. Drea, of Derwood, Md., Elaine P. Moore, of Stuttgart, Germany, and Doris C. Allen, of Crofton, Md., and two granddaughters.

The family suggests that expressions of sympathy be in the form of contributions to the Sacred Heart Home, 5805 Queen's Chapel rd., Hyattsville, Md., or to the American Heart Association.