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.