Kozelets (Ukrainian: Козелець; Russian: Козелец) is a historic town located in Chernihiv Oblast (province) of northern Ukraine. Kozelets is located on the Oster River, a tributary of the Dnieper. The city's estimated population is 8,305 (as of 2007).
The town was first mentioned in written documents in 1098, but its status as an urban-type settlement (a step below that of a city) was granted in 1924. It serves as the administrative center of the Kozelets Raion (district) housing the raion's administrative structure.
Notable attractions in the city includes the Cathedral of the Nativity of the Blessed Virgin designed in the Ukrainian Baroque style by architects Ivan Hryhorovych-Barskyi and Andrei Kvasov according to a plan by imperial architect Francesco Bartolomeo Rastrelli. Kozelets also houses several local food industries, and a veterinary technicum.
Kozelets was first mentioned in 1098 as a fortified town in the East Slavic state of Kievan Rus'. During times of the Polish-Lithuanian Commonwealth, Kozelets was known by the name Kozlohrad (Ukrainian: Козлоград).