Margaret Olivia Slocum Sage was born in Syracuse, New York on September 8, 1828. After attending the Troy Female Seminary (later the Emma Willard School), she married Russell Sage, a railroad magnate and Wall Street financier.

Upon the death of her husband, Mrs. Sage inherited $70,000,000, which she promptly used to establish the Russell Sage Foundation in 1907. An active suffragist, she also created Russell Sage College in Troy, New York, which aimed to encourage independence in women by furthering their education. Her personal interest in educational philanthropy included Rensselaer Polytechnic Institute and the Emma Willard School. She was also involved in Christian and women's charities such as the YMCA and Camp Fire Girls. In addition, she was extremely active in her home state of New York, both in the Capital Region and New York City. Mrs. Sage also established the Marsh Island bird sanctuary off the coast of Louisiana between Vermillion Bay and the Gulf of Mexico.

Olivia Sage died on November 4, 1918 in New York City.