Theodora Nathalia "Tonie" Nathan (born 9 February 1923) is the first woman to have received an electoral vote in a U.S. presidential election. She was the 1972 Libertarian candidate (on the ticket with John Hospers) for vice president when Roger MacBride, a Republican elector from Virginia cast the historic vote.

Born in New York City, Nathan trained in California as an insurance agent and worked in that field before switching careers to journalism and earning a bachelor's degree from the University of Oregon in 1971. Following her groundbreaking presidential run, which netted the Libertarian party its first electoral vote ever, she made a series of unsuccessful runs as a Libetarian candidate during the 1970s, including for U.S. House and Senate. She also chaired the Oregon Libertarian Party and served on the National Executive Committee of the United States Libertarian party.

She is married to Charles "Chuck" Nathan and lives in Eugene, Oregon; they have one son.