Roger Nash Baldwin (January 21, 1884 – August 26, 1981) was one of the founders of the American Civil Liberties Union (ACLU). He served as executive director of the ACLU until 1950.
Many of the ACLU's original landmark cases took place under his direction, including the Scopes Trial, the Sacco and Vanzetti murder trial, and its challenge to the ban on James Joyce's Ulysses. Baldwin was a well known pacifist and author.
Roger Nash Baldwin was born in Wellesley, Massachusetts to Frank Fenno Baldwin and Lucy Cushing Nash. He earned his bachelor's and master's degrees at Harvard University; afterwards, he moved to St. Louis on the advice of Louis D. Brandeis. There he taught sociology at Washington University, worked as a social worker and became chief probation officer of the St. Louis Juvenile Court. He also co-wrote Juvenile Courts and Probation with Bernard Flexner at this time; this book became very influential in its era, and was, in part, the foundation of Baldwin's national reputation.