The current study tested a new interpersonal model of disordered eating behaviours, whereby maladaptive schemas and theory of mind decoding (ToM-decoding) were related with disordered eating attitudes (body dissatisfaction) and behaviours (binging/purging and food restriction) through the mediating variable appearance-based rejection-sensitivity. A secondary aim was to test whether this model differed between two cultural groups: Caucasian Australian women (N = 197, ages ranging 17-43, M = 19.25, SD = 3.10), and Asian women living in East-Asia (N = 195, ages ranging 18-40, M = 28.60, SD = 5.15). Participants completed an online survey assessing the variables of interest. While the model showed acceptable fit for both groups, invariance testing demonstrated that the model worked differently in each group. Appearance-based rejection-sensitivity mediated the effect of maladaptive schemas on body dissatisfaction and disordered eating in both groups, but only mediated the effect of ToM-decoding on body dissatisfaction in the East-Asian group. Overall, the significant indirect pathways were greater in strength and number for the Caucasian-Australian group. These findings indicate that while the relationships between maladaptive schemas, appearance-based rejection-sensitivity, and disordered eating attitudes and behaviours are present in both cultures, ToM-decoding may only play a role for East-Asian participants.