Donji Zagon is located in the City of Novi Vinodolski, in Primorje-Gorski Kotar County at an elevation of 219 meters above sea level and it covers the area of 3.53 km² (1.36 sq. miles). According to the 2011 census report, there were 143 inhabitants. It is predominantly populated by Croats (96%), but also Serbs (3%). Nearby places: Ledenice, Povile, Bater, Novi Vinodolski, Crno, Klenovica, Gornji Zagon, Bribir, Smokvica Krmpotska and Drinak.