Shahr-e Zow (; formerly, Zavini-ye Pa'in , also Romanized as Zavini-ye Pa’in and Zavin-e Pa’in, also known as Zoo Sofla, Zow-e Pa’in, Zao Pain, Zow Sofla, and Zu-ye Soflá) is a city in and the capital of Zavin District, in Kalat County, Razavi Khorasan Province, Iran. At the 2006 census, its population was 4,053, in 959 families.