ABSTRAK Penelitian ini dilakukan pada anggota Organisasi Mapala Piranha Fakultas Perikanan dan Ilmu Kelautan Universitas Lambung Mangkurat dengan tujuan untuk mengetahui pengaruh peran kepemimpinan terhadap perilaku pro-lingkungan. Metode penelitian ini menggunakan teknik pengambilan subjek dengan purposive sampling. Subjek pada penelitian ini adalah anggota Organisasi Mapala Piranha yang memiliki nomor register keanggotaan sebanyak 30 orang. Pengumpulan data menggunakan skala peran kepemimpinan dan skala perilaku pro-lingkungan. Berdasarkan analisis data menggunakan analisis regresi linier sederhana diperoleh nilai t hitung sebesar 3,350 dengan taraf signifikansi 0,002 (p < 0,05) > t tabel sebesar 2,048, yang memiliki arti bahwa adanya pengaruh positif peran kepemimpinan terhadap perilaku pro-lingkungan pada anggota Mapala Piranha Fakultas Perikanan dan Ilmu Kelautan Universitas Lambung Mangkurat. Pengaruh peran kepemimpinan terhadap perilaku pro-lingkungan anggota Mapala Piranha sebesar 28,6% dengan klasifikasi besar persentase indikator peran interpersonal sebesar 9,7%, indikator peran informasional sebesar 9.45%, dan indikator peran pengambilan keputusan sebesar 9,45%. Kesimpulan dari penelitian ini adalah semakin baik peran kepemimpinan yang dijalankan, maka semakin baik pula perilaku pro-lingkungan anggota Organisasi Mapala Piranha Fakultas Perikanan dan Ilmu Kelautan Universitas Lambung Mangkurat. Kata Kunci : Peran Kepemimpinan, Perilaku Pro-lingkungan, Organisasi Pecinta Alam. ABSTRACT The Student Organization of Nature Lovers (Mapala) has activities which are pro-environment-oriented such as reforestation, preservation of environment and conservation of natural resources. Pro-environmental behavior within the organization can be influenced by the the role of leadership. This study was conducted in the members of MAPALA Piranha at the Faculty of Fisheries and Marine Science, Lambung Mangkurat University and aimed to find out the influence of leadership role on pro-environmental behavior. The method used in this study was the subject selection technique with purposive sampling. The subjects were 30 members of Mapala Piranha having membership registration numbers. Data were collected using a scale of leadership role and a scale of pro-environmental behavior. Based on simple linear regression analysis of the data, it obtained that the value of t count was 3.350 with significance level 0.002 (p < 0.05) > t table of 2.048, which meant that there was a positive influence of leadership role on pro-environmental behavior in the members of Mapala Piranha at the Faculty of Fisheries and Marine Science, Lambung Mangkurat University. The influence of leadership role on pro-environmental behavior in the members of Mapala Piranha was 28.6% with the classification of indicator percentage of interpersonal role by 9.7%, informational role by 9.45%, and decision-making role by 9.45%. It can be concluded from this study that the better the leadership role, the better the pro-environmental behavior in the members of Mapala Piranha at the Faculty of Fisheries and Marine Science, Lambung Mangkurat University. Keywords : leadership role, pro-environmental behaviour, organization of nature love