Brvnik
Brvnik is a village in the municipalities of Domaljevac-Šamac, Posavina Canton and Šamac, Republika Srpska, Bosnia and Herzegovina.
Demographics
According to the 2013 census, its population was 296, with 256 living in the Šamac part and 40 in the Domaljevac-Šamac part.| Ethnicity | Number | Percentage |
| Serbs | 283 | 95.6% |
| Croats | 3 | 1.0% |
| Bosniaks | 1 | 0.3% |
| other/undeclared | 9 | 3.0% |
| Total | 296 | 100% |