Mary Greenleaf Clement Leavitt (September 22, 1830 – February 5, 1912) was an educator and successful orator who became the first round-the-world missionary for the Woman's Christian Temperance Union (WCTU). Setting out on virtually non-stop worldwide tours over a decade, she "went to all continents save Antarctica," where she crusaded against alcohol and its evils including domestic violence; and advocated for women's suffrage and other equal rights such as higher education for women. In 1891 she became the honorary life president of the World's WCTU.