Badal Sircar’s Third Theatre represents one of the most significant interventions in modern Indian theatre through its radical reconfiguration of the actor-spectator relationship. Rejecting the conventions of the proscenium stage, illusionistic representation, and passive spectatorship, Third Theatre establishes an interactive performance space grounded in spatial intimacy, direct communication, and collective participation. This paper examines how Sircar’s theatrical practice redefines the classical Aristotelian concept of catharsis by transforming the audience from detached observers into active participants in the dramatic process. Drawing upon performance theory, audience studies, and postcolonial theatre criticism, the study analyzes select plays, including Evam Indrajit, Bhoma, Michhil (Procession), and Stale News, to explore the ways in which direct interaction, minimal staging, physical performance, and the dissolution of the fourth wall reshape spectatorship. The paper argues that Sircar replaces the traditional notion of catharsis as emotional purgation with a model of critical engagement that encourages ethical reflection, social awareness, and political responsibility. By situating Third Theatre in dialogue with the theatrical theories of Aristotle, Bertolt Brecht, Jerzy Grotowski, and Augusto Boal, the study demonstrates how Sircar develops a distinctly Indian mode of participatory theatre that challenges passive consumption and promotes collective consciousness. Ultimately, the paper contends that Third Theatre reimagines theatre not as a site of aesthetic escape but as a transformative social practice, thereby offering a new understanding of catharsis rooted in active citizenship, communal participation, and social change.