| United Socialist Workers' Party | |
| Native Name: | Partido Socialista de los Trabajadores Unificado |
| Colorcode: | Red |
| Foundation: | 2011 |
| Ideology: | Trotskyism Morenism |
| International: | IWLfi |
| Country: | Argentina |
| Abbreviation: | PSTU |
The United Socialist Workers' Party (Partido Socialista de los Trabajadores Unificado, PSTU) is the Argentine section of the International Workers' League (Fourth International) (LIT), a Trotskyist-Morenoist grouping.
It was formed in 2011 by the fusion of the FOS and the COI, two groups associated with the LIT.