Frank Rudolph Crosswaith (1892–1965) was a longtime socialist politician and activist and trade union organizer in New York City. Crosswaith is best remembered as the founder and chairman of the Negro Labor Committee, which was established on July 20, 1935 by the Negro Labor Conference.
Frank R. Crosswaith was born on July 16, 1892 in Frederiksted, St. Croix, Danish West Indies (the island was sold to the United States in 1917 and became part of the U.S. Virgin Islands), and emigrated to the United States in his teens. While finishing high school, he worked as an elevator operator, porter and garment worker. He joined the elevator operators' union and when he finished high school, he won a scholarship from the socialist The Jewish Daily Forward to attend the Rand School of Social Science, an educational institute in New York City associated with the Socialist Party of America.
Crosswaith founded an organization called the Trade Union Committee for Organizing Negro Workers in 1925, but this work went by the wayside when Crosswaith accepted a position as an organizer for the fledgling Brotherhood of Sleeping Car Porters. Crosswaith maintained a long association with union head A. Philip Randolph, serving with him as officers of the Negro Labor Committee in the 1930s and 1940s.
In the early 1930s Crosswaith worked as an organizer for the International Ladies' Garment Workers' Union, which became one of the major supporters of the Negro Labor Committee.
In 1924, he ran on the Socialist ticket for Secretary of State of New York, and in 1936 for Congressman-at-large. He ran also for the New York City Council in 1939 on the American Labor ticket.