Theodore Nathan Lerner (October 15, 1925 – February 12, 2023) was an American real estate developer and managing principal owner of the Washington Nationals baseball team.

[1] He was the founder of the real estate company Lerner Enterprises, the largest private landowner in the Washington metropolitan area, which owns commercial, retail, residential, and hotel properties, as well as Chelsea Piers in New York City.

[3] Lerner was raised in an Orthodox Jewish family in Northwest Washington D.C.,[4][5] the eldest of three children born to Mayer, a 1921 emigrant from British Mandatory Palestine (modern day Israel), and Ethel, who immigrated from Lithuania.

[6] Among the Lerner Enterprises ventures is a partnership in Chelsea Piers, a 30-acre (12 ha) sports and entertainment complex on the Hudson River in New York City; the Tysons II commercial development; shopping centers including White Flint and Dulles Town Center; and thousands of homes and apartments, along with numerous office buildings.

[9] The Washington Nationals franchise (then known as the Montreal Expos) was formerly owned and operated by Major League Baseball from February 15, 2002, until the official transfer of ownership to Lerner on July 24, 2006.

[13] The Annette M. and Theodore N. Lerner Family Foundation provides support to many organizations, including: Food & Friends; The Hebrew University of Jerusalem; Shady Grove Adventist Hospital; Hadley's Park; the Weizmann Institute of Science; the Scleroderma Foundation of Greater Washington; YouthAids; Junior Achievement of the Greater Washington Area; the Charles E. Smith Jewish Day School; and the Jewish Community Center of Greater Washington, among many others.

Ted and his wife Annette are founding members of the United States Holocaust Memorial Museum in Washington, D.C.