Olga Hirshhorn, who began buying modern art while married to Joseph H. Hirshhorn, the founder of the Hirshhorn Museum and Sculpture Garden in Washington, and who over time became recognized as a serious collector in her own right, died on October 3 2015 at her home in Naples, Fla. She was 95. Her death was confirmed by her son John Cunningham. Mrs. Hirshhorn was running a small employment agency in Greenwich, Conn., in the early 1960s when she met her future husband, an oil and mining tycoon and art collector who had recently bought a house nearby and needed to hire help. The two hit it off, and in 1964, she became Mr. Hirshhorn’s fourth wife. Olga Zatorsky was born in Greenwich on April 26, 1920, to Ukrainian immigrants. In a rich town, the family was working class: Her father was a gardener and chauffeur, her mother a cook for some of the wealthy neighbors. At Greenwich High School, Olga was a champion tennis player, competitive swimmer, editor of the yearbook and president of her class. A year after graduating in 1939, she married her English teacher, John Cunningham, and by the age of 25 she had three sons. To make ends meet, she started a babysitting business, which evolved into her employment agency, Services Unlimited. After divorcing her husband and marrying Mr. Hirshhorn, she became a prominent figure in museum circles, serving on the boards of the Hirshhorn, the Corcoran and the Baker Museum. In her later years, Mrs. Hirshhorn, who divided her time between her homes in Martha’s Vineyard, Washington and Naples, Fla. In addition to her son John, a sculptor and professor at Skidmore College, she is survived by another son, Denis; five grandchildren; and a great-grandson. Her third husband, Robert Whittier Dudley, died of cancer a year after their marriage in 1985.