The Battle of Slivnitsa (Bulgarian: , Serbian: ) was a victory of the Bulgarian army over the Serbians on 1719 November 1885 in the Serbo-Bulgarian War. It solidified the unification between the Kingdom of Bulgaria and Eastern Rumelia.

The Serbo-Bulgarian War or the Serbian–Bulgarian War (Bulgarian: Сръбско-българска война, Srăbsko-bălgarska voyna, Serbian: Српско-бугарски рат, Srpsko-bugarski rat) was a war between the Kingdom of Serbia and Principality of Bulgaria that erupted on 14 November [O.S. 2 November] 1885 and lasted until 28 November [O.S. 16 November] 1885. Despite Bulgaria being a vassal state of the Ottoman Empire, the Turks did not intervene in the war. Serbia took the initiative in starting the war but was decisively defeated. Austria demanded Bulgaria stop its invasion, and a truce resulted. Final peace was signed on 3 March [O.S. 19 February] 1886 in Bucharest. The old boundaries were not changed. As a result of the war, European powers acknowledged the act of Unification of Bulgaria which happened on 18 September [O.S. 6 September] 1885.