Reuben George Soderstrom (March 10, 1888 – December 15, 1970) was an American leader of organized labor who served as President of the (ISFL) and from 1930 to 1970. A key figure in Chicago and Illinois politics, he also played a pivotal role in American labor history by helping to define national labor policy after the formation of the AFL–CIO in 1955. Soderstrom advised and was courted by multiple U.S. presidents seeking his endorsement and the votes of the over 1.3 million laborers he represented. The longest-serving state federation chief in American labor history, he passed seminal labor legislation and increased his organization's membership five-fold, transforming it into one of the most powerful labor bodies in the United States.