This thesis advances the understanding of brand polarization, a nascent concept in the marketing and branding academic literature. Brand polarization is defined as an affective phenomenon that involves passionate positive and negative feelings and offers a new analytical lens to the consumer-brand relationship knowledge. The current thesis addresses the nature, drivers and outcomes of the brand polarization phenomenon and answers three research questions. To better understand brand polarization, the theoretical development involves a systematic literature review of five related concepts (polarization in political science, polarization in social psychology, brand rivalry, brand love and brand hate) and lie foundation for the development of a new conceptual model. The empirical analysis adopts a sequential mixed-methods research design with a qualitative and a quantitative study, where data is first collected via 22 semi-structured interviews, followed by a survey of 1,238 lovers and haters of polarizing brands in three different product categories. Consistent with the RQ2 and RQ3, the qualitative study utilises semi-structured interviews to identify the key antecedents and outcomes of brand polarization, and these preliminary insights inform the dimensionality of the phenomenon and the finalised conceptual model. Survey data was used to confirm the relationships hypothesised in the conceptual model and answer the RQ2 and RQ3. The thesis findings show the multi-dimensional nature of brand polarization, which consists of brand passion, self-brand benchmarking, intra-group identification and inter-group dissociation, and offer a new reliable measurement for the phenomenon. The results also identify five drivers of brand polarization, namely brand strength, brand uniqueness, association with important issues, ideological compatibility/incompatibility and sense of community. Finally, the evidence supports the role of brand polarization in pairs of oppositional concepts including complimenting and complaining behaviours; brand loyalty and disloyalty; using pro and anti-brand merchandise; participation in a brand and anti-brand community; forgiveness and retaliation behaviours; positive and negative WoM; and defending and attacking the brand. The research offers several theoretical, methodological and managerial implications.