The Treaty of Bucharest (Romanian: Tratatul de la Bucureti; Serbian: ; Bulgarian: ; Greek: ) was concluded on 10 August 1913, by the delegates of Bulgaria, Romania, Serbia, Montenegro and Greece. The Treaty was concluded in the aftermath of the Second Balkan War and amended the previous Treaty of London, which ended the First Balkan War. About one month later, the Bulgarians signed a separate border treaty (the Treaty of Constantinople) with the Ottomans, who had regained some territory west of the Enos-Midia Line during the second war.

The Second Balkan War was a conflict which broke out when Bulgaria, dissatisfied with its share of the spoils of the First Balkan War, attacked its former allies, Serbia and Greece, on 16 (O.S.) / 29 (N.S.) June 1913. Serbian and Greek armies repulsed the Bulgarian offensive and counter-attacked, entering Bulgaria. With Bulgaria also having previously engaged in territorial disputes with Romania and the bulk of Bulgarian forces engaged in the south, the prospect of an easy victory incited Romanian intervention against Bulgaria. The Ottoman Empire also took advantage of the situation to regain some lost territories from the previous war. When Romanian troops approached the capital Sofia, Bulgaria asked for an armistice, resulting in the Treaty of Bucharest, in which Bulgaria had to cede portions of its First Balkan War gains to Serbia, Greece and Romania. In the Treaty of Constantinople, it lost Adrianople to the Ottomans.

The political developments and military preparations for the Second Balkan War attracted an estimated 200 to 300 war correspondents from around the world.