Consumptive behaviour is an excessive buying behaviour that is particularly based more on mere desires rather than needs. Consumptive behaviour can be influenced by self-esteem and conformity. This study aimed to determine the mediating role of conformity on the relationship between self-esteem and consumptive behaviour. Participants were 344 students from 10 faculties of the Muhammadiyah University of Malang. The data were analysed using a mediation model. The results showed as hypothesised that the negative relationship between self-esteem and consumptive behaviour was significantly mediated by conformity. Perilaku konsumtif merupakan perilaku membeli yang berlebihan yang didasarkan teruatam pada keinginan semata dan bukannya berdasarkan pada kebutuhan. Perilaku konsumtif dapat dipengaruhi oleh faktor harga diri dan konformitas. Penelitian bertujuan untuk menguji peran konformitas dalam memediasi hubungan antara harga diri dan perilaku konsumtif. Subjek penelitian adalah 344 mahasiswa dari 10 fakultas di Universitas Muhammadiyah Malang. Data hasil penelitian dianalisis menggunakan model mediasi. Hasil penelitian menunjukkan, sesuai dengan hipotesis yang diajukan, bahwa hubungan negatif antara harga diri dan perilaku konsumtif secara signifikan dimediasi oleh konformitas.