The expansion of social commerce has reshaped contemporary consumer purchasing patterns, particularly on short-video platforms such as TikTok Shop. This study investigates the key determinants of consumer purchase intention within the TikTok Shop environment in Malaysia by extending the Theory of Planned Behavior (TPB) to incorporate brand-related and perceived quality factors. A quantitative research approach was adopted, and survey responses were obtained from urban TikTok users in the Klang Valley. The proposed relationships were examined through multiple regression procedures. The findings indicate that attitude, perceived quality, brand image, perceived behavioral control, and subjective norm each have a significant positive influence on purchase intention. Among these factors, attitude and perceived quality demonstrate comparatively stronger explanatory power, highlighting the importance of experiential engagement and evaluative judgments in short-video-driven retail contexts. The results further illustrate how branding cues and quality perceptions operate within algorithm-based and influencer-mediated commerce settings. By providing empirical evidence from an emerging Southeast Asian market, this study enriches the social commerce literature and offers practical implications for marketers, platform managers, and policymakers aiming to strengthen consumer trust and participation in digital retail environments.