The Indonesian Ichthyological Society (Masyarakat Iktiologi Indonesia, or MII) is a non-profit scientific organization established to support and advance the study of ichthyology—the science of fishes—in Indonesia. Founded on June 6, 2000, during a national seminar on fish biodiversity in Bogor, the society brings together researchers, academics, students, practitioners, NGOs, and fish enthusiasts from across the country. It aims to be a leading institution in promoting knowledge and conservation of fish diversity in freshwater, brackish, and marine environments. MII organizes seminars, congresses, and international conferences such as the International Seminar on Fish and Fisheries Sciences (ISFFS).