This paper examines the influence of brand relationship quality (BRQ) on brand loyalty within the sphere of social commerce and explores how cultural values could moderate this impact. Consistent with prior research, our results confirm a positive correlation between BRQ and brand loyalty. Importantly, this research highlights the moderating role that cultural values play in building brand loyalty, underscoring their significance and the need to consider them carefully. Specifically, customers with high indices in individualism, masculinity and power distance display greater brand loyalty when BRQ is high. Conversely, those with lower scores on the indulgence and long-term orientation dimensions tend to exhibit stronger brand loyalty when BRQ is high. This study underlines the importance of integrating cultural values when building brand loyalty within the sphere of social commerce, contributing new insights into the complex interplay between culture and consumer behaviour in digital environments.