<p>Status hierarchy, defined as within-group differentiation in individual status, ranging from egalitarian to hierarchical, is a common phenomenon in adolescents’ peer groups. However, the implications of peer group status hierarchy for individual adjustment remain unclear in different social and cultural contexts. This two-wave longitudinal study with an interval of 10 months aimed to explore how peer group status hierarchy was associated with loneliness and how group support mediated the associations in Chinese and Canadian adolescents. Participants were fourth- to eighth-grade students in urban China (<i>n</i> = 787; 343 girls; <i>M</i>age = 12.55 years) and Canada (<i>n</i> = 1033; 589 girls; <i>M</i>age = 11.81 years). Data on group status hierarchy, group support, and loneliness were obtained from self-reports. Results indicated that greater status hierarchy within groups was associated with higher loneliness in both countries. However, the mediating effect of group support differed. In Canada, greater group status hierarchy predicted lower peer support, leading to increased loneliness, whereas in China, greater status hierarchy predicted higher peer support, which subsequently reduced loneliness. These findings highlight both similarities and differences in the functional meanings of adolescents’ peer group hierarchy in Chinese and North American societies.</p>