Konstantin Sergeyevich Stanislavski was a seminal Soviet Russian theatre practitioner. He was widely recognized as an outstanding character actor, and the many productions that he directed garnered him a reputation as one of the leading theatre directors of his generation. His principal fame and influence, however, rests on his "system" of actor training, preparation, and rehearsal technique.

Stanislavski's system is a systematic approach to training actors that the Russian theatre practitioner Konstantin Stanislavski developed in the first half of the twentieth century. His system cultivates what he calls the "art of experiencing". It mobilises the actor's conscious thought and will in order to activate other, less-controllable psychological processes—such as emotional experience and subconscious behaviour—sympathetically and indirectly. In rehearsal, the actor searches for inner motives to justify action and the definition of what the character seeks to achieve at any given moment.