Beatty was married four times, the first three times to Americans. His first marriage was to Dorothy Carlotta (née Power) Sands on 21 April 1937, an older sister of Thomas Sarsfield Power (later the United States Air Force General in World War II to direct the dropping of the atomic bombs on Japan). David and Dorothy (who had previously been married to LaFrance Adelbert Mitchell, Harry Estie Reynolds Hall, and Edward Van Volkenburgh Sands) were divorced in 1945. She next married and divorced John Gordon Baragwanath and then, on 10 December 1954, she was married to Peregrine Francis Adelbert Cust, 6th Baron Brownlow, remaining married until her death in 1966.