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We report room‐temperature bulk plasticity mediated by dislocations in single‐crystal cubic potassium tantalate oxide (KTaO₃), contrasting the conventional knowledge that single‐crystal KTaO₃ is susceptible to brittle fracture. A mechanics‐based combinatorial experimental approach using cyclic Brinell indentation, scratching, and uniaxial bulk compression consistently demonstrates room‐temperature dislocation plasticity in KTaO₃ from the mesoscale to the macroscale. This approach also delivers tunable dislocation densities and plastic zone size. Scanning transmission electron microscopy analysis underpins the activated slip system to be <110> {11¯0}. Given the growing significance of KTaO₃ as an emerging electronic oxide and the increasing interest in dislocations for tuning the physical properties of oxides, our findings are expected to trigger synergistic research interest in KTaO₃ with tunable dislocation densities.