Brand activism has emerged as a strategic tool through which corporations influence social change, policy debates, and moral discourse. While research previously centered on corporate social responsibility (CSR), modern activism demands public political engagement on issues such as labor rights, gender equality, climate change, censorship, racial justice, and democratic freedoms. This study examines how brand activism differs across political systems—liberal democracies, hybrid regimes, authoritarian states, and fragile/post-conflict states. Using mixed-method research including expert interviews, policy analysis, and case studies from multinational corporations, the study finds that political context determines not only messaging strategies but also risk levels, public legitimacy, regulatory response, and stakeholder alignment. A comparative framework is proposed to guide activism across varied political environments.