Šamac, formerly Bosanski Šamac is a town and municipality in Republika Srpska, Bosnia and Herzegovina. There are also small, uninhabited, …Šamac, formerly Bosanski Šamac is a town and municipality in Republika Srpska, Bosnia and Herzegovina. There are also small, uninhabited, parts located in the municipalities of Odžak and Domaljevac-Šamac, Federation of Bosnia and Herzegovina.