Bijeljina (Бијељина) is a city in northeastern Bosnia and Herzegovina in the Republika Srpska entity. The city is situated in the plain of Semberija, close to the borders of both Croatia and Serbia and Montenegro.
At the 1991 census, Bijeljina county had 96,796 inhabitants; 59% of whom were Serbs and 31% Muslims. At present, the town has 105,000 inhabitants (estimate), 98.75% of whom are Serbs.