In Trotskyist political theory, deformed workers' states are states where capitalism has been overthrown through social revolution and the property forms have changed into a collectivized planned economy, but where the working class has never held political power (as it did in Russia shortly after the Russian Revolution). These workers' states are deformed because their political and economic structures have been imposed from the top (or from outside), and because the people have no real power. A deformed workers' state is an incomplete form of socialism - it has a planned economy, but not the democracy that is necessary for any fully socialist system.

The concept of deformed workers' states was developed by the theorists of the Fourth International after World War II, when the Soviet Union had created satellite states in Eastern Europe. Taking Leon Trotsky's concept of the Soviet Union as a degenerated workers state, the Trotskyists described the new regimes as deformed workers' states.

Rather than advocating a full revolutionary programme, they came to advocate a political revolution to oust the Stalinist bureaucracy.

Other Trotskyists disagreed with this interpretation, and adopted other theories, describing the Soviet Union as being state capitalist or bureaucratic collectivist.

Orthodox Trotskyists cite examples of deformed workers' states today as including Cuba, the People's Republic of China, North Korea and Vietnam. The Committee for a Workers International has also included states such as Syria or Burma at times when they have had a nationalised economy.

Compare with other left-wing theories regarding Soviet-style societies: new class, state socialism, state capitalism, bureaucratic collectivism and coordinatorism.