Sigmund G. Livingston (December 27, 1872 – June 13, 1946) was a German-born American Jewish attorney, jurist, and civil rights activist who founded the Anti-Defamation League (ADL) in 1913 under the auspices of the Independent Order of B'nai B'rith, serving as its inaugural national chairman until 1945. Born in Germany, he immigrated to the United States and established a legal practice in Chicago, Illinois. In response to rising antisemitic incidents in the early 20th century, he created the ADL to combat antisemitism through legal, educational, and public relations means, focusing on non-confrontational strategies like fact-finding and dialogue. Under his leadership, the organization expanded with regional offices and initiatives to counter prejudice in media, education, and public life. Livingston authored the book 'Must Men Hate?' in 1944, exploring the roots of prejudice and advocating for tolerance. His foundational work shaped modern anti-discrimination movements, and the ADL established the Sigmund Livingston Award and Sigmund Livingston Fellowship in his honor. He is remembered as a pioneer in human rights activism whose German-Jewish heritage and American legal training informed his commitment to justice.