The rapid growth of digital commerce has reshaped the foundations of branding by enabling the emergence of online-first entities that achieve legitimacy through symbolic visibility rather than extensive physical presence. This study conceptualizes such entities as phantom brands—brands that gain recognition through digital aesthetics, social proof, influencer association, and algorithmic amplification. The study examines how phantom brands influence consumer behaviour in India, with evidence from Madurai, Tamil Nadu. Primary data were collected from 300 respondents using a structured questionnaire. Statistical tools including descriptive statistics, Cronbach's alpha, correlation, factor analysis, and multiple regression were employed. Results indicate that consumer trust is the strongest predictor of purchase intention, followed by social proof and digital symbolism. Younger respondents showed greater receptivity toward digitally visible brands, while repeated online exposure enhanced perceived credibility. The findings suggest a shift from material legitimacy to platform-mediated legitimacy in contemporary markets. The study contributes to branding literature by introducing phantom brands as an emerging construct relevant to developing economies.