Focșani lies in Moldova, at the boundary between the historical Romanian regions of Moldova and Wallachia. It is located at the crossroads of road and European railway network, being crossed by the railway corridor No. 9 (Helsinki-Moscow-Chisinau-Bucharest-Plovdiv) and may benefit from the proposed expansion of the road corridor No. 1 (Tallinn-Warsaw-Chernivtsi-Bucharest).
Focsani is geographically situated at 45 degrees and 42 min. North latitude with the 26 degrees and 13 min. East longitude, guarding the South-Eastern Curvature Carpathians, at the contact between lower Siret Plain inferior and Carpathian hills that culminates with Magura Odobeștilor (1.001 m). Focșani has an area of 54,8 km ², representing 1% of Vrancea County, being a medium sized town.