Nellie Davis Tayloe Ross (November 29, 1876 – December 19, 1977) was an American politician who served as the 14th governor of Wyoming from 1925 to 1927, and as the 28th director of the United States Mint from 1933 to 1953. She was the first woman to serve as governor of a U.S. state, and remains the only woman to have served as governor of Wyoming.Ross was born in St. Joseph, Missouri, to James Wynns Tayloe, a native of Tennessee, and Elizabeth Blair Green, who owned a plantation on the Missouri River. Her family moved to Miltonvale, Kansas in 1884, and she graduated from Miltonvale High School in 1892. She attended a teacher-training college for two years and taught kindergarten for four years.

On September 11, 1902, Ross married William B. Ross, whom she had met when visiting relatives in Tennessee in 1900. William B. Ross was governor of Wyoming from 1923 to his death on October 2, 1924. Ross succeeded her late husband's successor Frank Lucas as governor when she won the special election, becoming the first female American governor on January 5, 1925. She was a staunch supporter of Prohibition during the 1920s. She lost re-election in 1926, but remained an active member of the Democratic Party.

In 1933, Ross became the first female Director of the United States Mint. Despite initial mistrust, she forged a strong bond with Mary Margaret O'Reilly, the Assistant Director of the Mint and one of the United States' highest-ranking female civil servants of her time. Ross served five terms as Director, retiring in 1953. During her later years, she wrote for various women's magazines and traveled. Ross died in Washington, D. C., at the age of 101.