ABSTRACTResearch Question/IssueUsing a sample of Chinese listed firms between 2010 and 2020, this study examines the effect of minority shareholders' online voice on controlling shareholders' tunneling.Research Findings/InsightsWe find that minority shareholders' online voice significantly reduces controlling shareholders' tunneling. The effect is more pronounced in firms with higher information asymmetry and weaker investor protection. We further show that minority shareholders' online voice can attract additional attention from other investors and regulators, exerting market and regulator pressure on controlling shareholders. Additional analysis also suggests that the effect of minority shareholders' online voice on controlling shareholders' tunneling increases with the negative tone of the questions and decreases with firms' responsiveness to these questions.Theoretical/Academic ImplicationsPast findings of the governance role of minority shareholders mainly focus on their voting rights, but less attention has been paid to their online activism through voice. Our results suggest that minority shareholders' online voice plays an important role in corporate governance by curbing the controlling shareholders' tunneling attempt.Practitioner/Policy ImplicationsThis study provides an essential implication for the regulators in emerging capital markets that adopting the online interactive platforms for firms and investors helps to enhance the minority shareholders' monitoring role.