P. L. Siemiller

Paul LeRoy "Roy" Siemiller (September 4, 1904 – June 2, 1993) was an American labor union leader.

Born in Gothenburg, Nebraska, Siemiller grew up in California, Arkansas, and then St. Cloud, Florida. He then traveled to undertake short-term work until he settled in Atlanta and completed an apprenticeship as a machinist. He joined the International Association of Machinists (IAM) in 1929, while working in Port Arthur, Texas, then moved to Harrison, Arkansas to work for the Missouri and Northern Arkansas Railroad.

Siemiller became financial secretary and then president of his local union. In 1937, he began working full-time for the international union, organizing workers on the Pennsylvania Railroad. During World War II, he served on the Sixth Regional War Labor Board. He was the American Federation of Labor delegate to the International Labour Organization in 1947, and in 1948, he was elected as a vice-president and executive board member of the IAM. For six months in 1951, he served as director of the manpower division of the Defense Transport Administration.