Ključar is located in the municipality Vojnić, in Karlovac County at an elevation of 180 meters above sea level and it covers the area of 7.41 km² (2.86 sq. miles). According to the 2011 census report, there were 81 inhabitants. It is largely populated by Serbs (85%), but also Croats (15%). Nearby places: Radonja, Brdo Utinjsko, Vojišnica, Krivaja Vojnićka, Gačeša Selo, Jurga, Kokirevo, Vojnić, Međeđak Utinjski and Crevarska Strana.