Dean Reese Merrill, 73, a budget and finance officer with the State Department who retired in 1972 after more than 30 years of federal service, died of cancer Monday at George Washington University Hospital.

Mr. Merrill, who was born in Logan, Utah, attended Utah State University and moved to Washington in 1935. He worked in the Senate Post Office and attended night classes at the law school of George Washington University, where he earned his degree in 1942 and was admitted to the D.C. Bar.

In the same year, he joined the wartime Office of Price Administration. After World War II, he worked for the Department of the Army. He joined the State Department in 1956 and became a Foreign Service Reserve Officer. Mr. Merrill's work always concerned budget and financial matters. Some of it involved foreign assistance programs.

A resident of Rockville at the time of his death, Mr. Merrill's hobbies included gardening.

His marriage to the former Josephine Smith ended in divorce.

Survivors include his wife, Eleanor McCarthy Merrill of Rockville, and their three children, Navy Lt. Cmdr. Dean Merrill Jr., who is stationed in Bremerton, Wash., Diane Melis of Rockville, and Linda Pemberton of Gaithersburg; a son by his first marriage, David Voda of Salt Lake City; a brother, Asa J. Merrill of Cumberland, Md., and 13 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Children's Hospital National Medical Center, Washington, D.C., or to a charity of one's choice.