Arsky District (Russian: А́рский райо́н; Tatar Cyrillic: Арча районы, Latin: Arça rayonı) is an administrative and municipal district (raion), one of the forty-three in the Republic of Tatarstan, Russia. It is located in the northwest of the republic. The area of the district is 1,843.6 square kilometers (711.8 sq mi). Its administrative center is the town of Arsk. Population: 51,667 (2010 Census); 51,343 (2002 Census); 61,959 (1989 Census).