Abstract Introduction: The purpose of the present study is to examine the role of multisensory experience in enhancing brand engagement and to explain the mechanisms through which sensory stimuli can strengthen customers’ relationships with brands. In today’s competitive markets, brands are no longer able to create sustainable differentiation merely through the functional features of products; rather, they need to create meaningful, distinctive, and memorable experiences for customers. Multisensory experience, by simultaneously or harmoniously engaging different senses such as sight, hearing, smell, touch, and taste, can enrich customers’ perception of the brand and provide the basis for deeper cognitive, emotional, and behavioral connections. Despite the importance of this issue, limited domestic studies have examined the role of multisensory experience in brand engagement, particularly in the Iranian cosmetics and personal care industry. Therefore, the main problem of this study is to determine through which dimensions and mechanisms multisensory experience can improve customer engagement with the brand. Methods: In terms of purpose, this research is applied, and in terms of method, it is a mixed-method study with an exploratory–descriptive approach, conducted in two qualitative and quantitative phases. In the qualitative phase, in order to identify the dimensions of multisensory experience affecting brand engagement, semi-structured interviews were conducted with 11 experts, including marketing professors, brand managers, and advertising professionals. Participants were selected purposefully, and data collection continued until theoretical saturation was reached. The qualitative data were analyzed using thematic analysis. At this stage, 236 initial codes, 44 basic themes, 12 organizing themes, and finally four overarching themes were extracted. In the quantitative phase, the statistical population consisted of customers of the Iranian cosmetic brand “Schon” who had used the brand’s products at least once. A researcher-made questionnaire was developed based on the results of the qualitative phase and the theoretical foundations, and after assessing its validity and reliability, it was distributed among 450 respondents. Finally, 400 valid questionnaires were analyzed. The data were analyzed using partial least squares structural equation modeling and SmartPLS software. Finding: The results of the qualitative phase showed that multisensory experience can enhance brand engagement through four main dimensions: unique experience, brand differentiation, decision-making acceleration, and cognitive–affective involvement. The findings of the quantitative phase also indicated that multisensory experience has a positive and significant effect on all four identified dimensions. Moreover, each of these dimensions directly influenced brand engagement. The results of the mediation tests also showed that unique experience, brand differentiation, decision-making acceleration, and cognitive–affective involvement play significant mediating roles in the relationship between multisensory experience and brand engagement. Among these dimensions, decision-making acceleration played a prominent role in reducing ambiguity, increasing confidence, and facilitating customer choice, while cognitive–affective involvement provided the basis for a deeper and more sustainable relationship between customers and the brand. Conclusions: Based on the findings, multisensory experience can transform a brand from a mere commercial sign into a tangible, meaningful, and distinctive experience. When a brand’s sensory stimuli are aligned with its identity, message, and values, customers perceive the brand as clearer, more trustworthy, and closer to their needs and expectations. This can lead to increased attention, interest, confidence, participation, and sustainable engagement with the brand. The results of this study provide important implications for brand managers, especially in the cosmetics and personal care industry. Brands can create a coherent and distinctive experience for customers by designing visual elements, scent, product texture, packaging, in-store music, digital content, and sensory words in a coordinated manner. In the online environment, the use of high-quality images, product application videos, and sensory descriptions can also partly compensate for the absence of physical experience and increase customer engagement with the brand. Keywords: Multisensory Experience, Brand Engagement, Brand Differentiation, Unique Experience, Decision-Making Acceleration, Cognitive–Affective Involvement, Schon Cosmetic Brand