ABSTRAK Penelitian tentang “Keanekaragaman dan Distribusi Ikan di Sungai Teunom Kabupaten Aceh Jaya” telah dilakukan pada bulan Agustus 2018 sampai dengan Juli 2019. Penelitian ini bertujuan untuk mengetahui keanekaragaman dan distribusi ikan yang terdapat di Sungai Teunom, Kabupaten Aceh Jaya, Provinsi Aceh. Penelitian ini menggunakan metode ‘purposive sampling’ berdasarkan kondisi lingkungan sepanjang aliran sungai. Sampel ikan dikoleksi dengan menggunakan alat pancing, bubu dan jaring. Hasil identifikasi menunjukkan bahwa terdapat 431 individu ikan yang terbagi ke dalam 11 famili dan 16 spesies. Spesies ikan yang banyak ditemukan yaitu famili Cyprinidae sebanyak 6 spesies yaitu Labtobarbus hosii, Anematichthys apogon, Rasbora sp., Tor tambroides, Osteochilus kappenii, dan Osteochilus vittatus. Indeks keanekaragaman kelima stasiun tergolong kriteria rendah-sedang dengan kisaran nilai 0,98-1,62. Sedangkan indeks kesamaan spesies ikan antar stasiun berkisar antara 0,0%-92,3%. Adapun kondisi fisika-kimia air Sungai Teunom tergolong optimum bagi keberlangsungan hidup ikan. Kata kunci: Sungai Teunom, Ikan, Keanekaragaman ABSTRACT Research on “Diversity and Distribution of Fish in Teunom River of Aceh Jaya Regency” was conducted in August 2018 until Juli 2019. This study aims to determine diversity and distribution of fish species found in Teunom River, Aceh Jaya Regency, Aceh Province. This research used an Exploration Method. Determination of reserch station was chosen by a purposive sampling based on environmental conditions along river flow. Fish samples were collected using fishing rods, traps, and nets. The results of identification indicate there were 431 individual fish that were divided into 11 families and 16 species. Fish species were commonly found from the family of Cyprinidae as with four species were six, namely Labtobarbus hosii, Anematichthys apogon, Rasbora sp., Tor tambroides, Osteochilus kappenii, dan Osteochilus vittatus. The diversity index of the five stations was classified as a low-moderate criteria with a value range of 0,98 to 1,62. While the similarity index of fish species between stations ranged from 0,0% to 92,3%. The physics-chemical condition of Teunom River water was considered to be optimum for the survival of fish. Keywords: Teunom River, Fish, Diversity