The Reverend Friar Thomas J. Hagerty (ca. 1862-?) was an American Roman Catholic priest from New Mexico, and one of the founding members of the Industrial Workers of the World (IWW).
Hagerty had been a Marxist before his ordination in 1892 and was later influenced by anarcho-syndicalism. He served at St. Agatha's Parish in Chicago. Moving to the Diocese of Dallas, he was stationed at St. Joseph's in Cleburne Texas, and then at Our Lady of Victory in Paris Texas. The mistreatment of Mexican railroad workers angered him, and he started translating socialist literature into Spanish. 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." Shortly afterwards, he was exiled by the Dallas Diocese and sent to the Archdiocese of Santa Fe, where he worked at a parish in Santa Fe New Mexico. His formal association with the Church ended when he was suspended by his archbishop for urging miners in Colorado to revolt during his tour of mining camps in 1903, however he continued to consider himself a priest in good standing.  Shortly after, he became the editor of the American Labor Union's newspaper, the Voice of Labor.
Hagerty is credited with authoring the IWW Preamble, assisting in writing the Industrial Union Manifesto and drawing up the first chart of industrial organization (dubbed "Father Hagerty's Wheel of Fortune" by Samuel Gompers).
Hagerty favored direct action, as opposed to political action of the socialist political parties (he referred to them as "slowcialists"). During an IWW convention speech he said:
- "The Ballot Box is simply a capitalist concession. Dropping pieces of paper into a hole in a box never did achieve emancipation of the working class, and in my opinion it never will."
 See also