Ćosinac is located in the City of Pleternica, in Požega-Slavonia County at an elevation of 136 meters above sea level and it covers the area of 2.64 km² (1.02 sq. miles). According to the 2011 census report, there were 54 inhabitants. It is mostly populated by Serbs (53%), but also Croats (48%). Nearby places: Sesvete, Grabarje, Granje, Lakušija, Šumanovci, Cerovac, Ašikovci, Bjeliševac, Zarilac and Rajsavac.