Thomas Joseph Hagerty (ca. 1862–1920s?) was an American Roman Catholic priest and trade union activist. Hagerty is remembered as one of the founding members of the Industrial Workers of the World (IWW), as author of the influential Preamble to the Constitution of the IWW, and as the creator of "Hagerty's Wheel," a frequently reproduced illustration depicting the interrelation of the IWW's constituent industrial unions.
Hagerty abruptly abandoned the radical movement shortly after the formation of the IWW, adopting the pseudonym "Ricardo Moreno" and working as a Spanish teacher and an oculist. After 1920 Hagerty lived on the streets of Chicago in conditions of dire poverty, eking out a meager existence as a beggar.
Little is known about the early years of Thomas Joseph Hagerty, prior to his completion of seminary training in 1895. He is believed to have become a Marxist about 1892 and to have spent his early life attempting to rectify the teachings of the church and the socialist movement throughout his early life.
Hagerty's first posting was to St. Agatha's Parish in Chicago in 1895, where he served as assistant to the rector. He was assigned to St. Joseph's Church in Cleburne, Texas in the Diocese of Dallas in 1897 before being promoted to rector of Our Lady of Victory Church in Paris, Texas in 1901. He was transferred to Our Lady of Sorrows Church in Las Vegas, New Mexico later that same year.
As a Catholic priest in the Southwestern United States Hagerty came into frequent contact with Mexican railroad workers, the mistreatment of whom by their employers angered him. Finding little socialist propaganda to be available in Spanish, Hagerty began translating a number of short works from German, French, and English. Hagerty was warned by the railroads to stay out of labor relations, he told a messenger "Tell the people who sent you here that I have a brace of Colts and can hit a dime at twenty paces."