チェルニーヒウ州
Kozelets Raion was located in the southwestern part of the Chernihiv Oblast, corresponding to the modern-day boundaries of the Polissia historical regions. To its west and south, it bordered upon Vyshhorod and Brovary Raions of Kyiv Oblast. Its total area constituted , constituting 8.3 percent of the total area of Chernihiv Oblast.