Retired Rear Adm. George J. Dufek, commander of the Navy's Antarctic Operation Deep Freeze and the first American to set foot on the South Pole, died Thursday at the Bethesda Naval Medical Center. It was his 74th birthday.

Adm. Dufek already had attained an enviable record as a submarine officer, commander of destroyers and carriers, and as a pilot, of air squadrons, when he selected in 1954 to head a special Antarctic planning group in connection withOperation Deep Freeze.

In March, 1955, he became commander of Task Force 43 of the Navy's 1955-59 Antarctic Expedition. He sailed for the Antarctic in November, 1955, for Operation Deep Freeze One. The Task Force built a major base at Little America and an air operating base at McMurdo Sound. The first operation was completed in three months.

In October, 1956, Adm. Dufek returned to Antarctica by Navy plane for Operation Deep Freeze Two. It was on the last day of that month that he became the first American to stand on the South Pole. (He was preceded earlier this century by Roald Amundsen of Norway and Robert F. Scott of Britain.) The Task Force built five more bases in Antarctica.

Adm. Dufek also participated in Operation Deep Freeze Three in 1959, before retiring that year.

Operation Deep Freeze was not his first experience with polar expeditions nor the first time he had worked with the late Adm. Richard E. Byrd, who died in 1957.

In 1939, he had volunteered to be part of Adm. Byrd's third expedition to Antarctica. He was navigator of the U.S.S. Bear, the flagship of the project.

In 1946, he was chief staff officer of a group that went to the Arctic to establish weather bases in the area of the North Pole. That same year, he participated in another Byrd expedition to Antarctic, known as High-jump.

In 1948, Adm. Dufek returned with a task force to the North Pole area to establish additional weather stations.

Born in Rockford, Ill., Adm. Dufek graduated from Annapolis in 1925.He served first on a submarine tender and then in submarines, where he was one of the few officers qualified to hold command posts without having attended submarine school.

In 1933, after training at the Naval Air Station in Pensacola, he became a pilot. Five years later he became operations officer of a scouting squadron on the carrier U.S.S. Saratoga.

After returning from his first trip to Antarctica, Adm. Dufek was sent to Jacksonville, Fla., to help establish the naval air station there in 1940. He was commanding officer of its first flight training squadron.

After the attack on Pearl Harbor, he was assigned to London as a special observer for naval aviation. During World War II, he was senior U.S. naval aviator with Northweat Africa Naval Forces and helped plan the successful invasions of Sicily and Salerno.

Adm. Dufek then transferred to Naples, where he assisted in the plans for the invasion of Southern France.

In the latter part of the war, he was commanding officer of the destroyer U.S.S Bogue, which sank the last German submarine lost in World War II.

After the European fighting ended, Adm. Dufek was ordered to the Pacific. He served briefly with occupation forces in Japan before going on his first Arctic expedition.

In between expeditions, he was on duty at the Navy Department in Washington, where he also attended the Industrial College of the Armed Forces.

In 1950, Adm. Dufek was placed in command of the aircraft carrier U.S.S. Antietam. He led that ship during 79 days of intensive combat operations during the Korean war.

Adm. Dufek's honors included the National Geographic Society's Hubbard Gold Medal.

His military decorations included the Distinguished Service Medal with Gold Star, the Legion of Merit with two Gold Stars, the Antartic Expedition Medal, the French Croix de Guerre and Legion of Honor, the Belguim Order of the Crown and the Swedish Geographical Society's Andre Medal.

Adm. Dufek was the author of two books, "Operation Deep Freeze" and "Through the Frozen Frontiers."

From 1960 until 1973, he directed the Mariners Museum in Newport News, Va., where he had lived since retiring from the Navy.

He was a member of the American Society of Naval Engineers, the American Geophysical Union, the Army and Navy Club here and the Explorers Club.

He is survived by his wife, Muriel Thomson Dufek, of the home; two sons, George J. Jr., of Atlanta, and Navy Lt. David Dufek; a daughter, Mrs. Bernard Bellit, of Menlo Park, Calif.; a sister, Mae Parker, of Fort Lauderdale, Fla., and four grandchildren.