Shostka is a city in Sumy Oblast, northeastern Ukraine. Shostka serves as the administrative center of Shostka Raion. Population: 71,966. The …Shostka is a city in Sumy Oblast, northeastern Ukraine. Shostka serves as the administrative center of Shostka Raion. Population: 71,966. The city lies on the Shostka River, a tributary of the Desna, from which it gets its name. Shostka is an important centre of industry: in chemicals and in dairy, the Shostka City Milk Plant was recently acquired by the Bel Group.