Ostrovo (Serbian Cyrillic: Острово,[5] Hungarian: Lászlófalva) is a village located in the Municipality of Markušica, within Vukovar-Syrmia County, eastern Croatia.

In the latter, it was part of the self-proclaimed Serb entity of SAO Eastern Slavonia, Baranja and Western Syrmia before being peacefully reintegrated into Croatia under UNTAES administration after the signing of the 1995 Erdut Agreement.

[6] Ostrovo was first mentioned in 1381 as a ruined town, leading historians to speculate that it was initially established during the existence of Valkó County.

[7] Before the Ottoman conquest, the surrounding land was owned by Benedictine monks, with nearby settlements such as Laslovo, Eginci, and Čakanovci forming part of the Ostrovo property.

[8] The Osijek Military Command negotiated with the peasants, who selected a three-member delegation—Ignjat Marić from Jarmina, Stojan Cvetković from Ostrovo, and Đuro Vuković from Cerić—to present their grievances in writing.

[9] By 1866, the village had a population of 629 residents living in 105 houses, with the majority belonging to the Eastern Orthodox Serb or Vlach communities.

[13] A firefighters’ unit began operations in 1936, and a post office opened in 1937, though it closed during World War II in Yugoslavia.

[14] The Croat community publication Hrvatski list from Vukovar claimed at the time that Serb mayors from Ostrovo and ten neighboring villages supported remaining within the Banovina of Croatia, a claim denied by the Vinkovci-based Serb publication Slavonija subsequently together with signatures of the mentioned mayors.

[15] The article in Slavonija denied that the meeting between mayors and Sava Kosanović of the Independent Democratic Party at which alleged support for the inclusion into the new Banovina of Croatia ever took place.

The NDH's Genocide of Serbs in the Independent State of Croatia and Romani Holocaust led to widespread atrocities, including the deportation of Ostrovo residents to the Jasenovac concentration camp as early as 1941.

[16] In 1942, a local teacher, Vasa Dobrić, noted the emergence of Yugoslav Partisan resistance in the area, though specific details remain scarce.

[16] In 1944, the Ustaše regime planned a massacre in Ostrovo during Orthodox Easter, but the intervention of local Croatian villagers from Nuštar prevented the attack.

[16] During the Socialist Federal Republic of Yugoslavia, Ostrovo underwent significant infrastructural and social changes, although some developments lagged behind neighboring villages.

[17] After six months of work, on November 2, Ostrovo celebrated the installation of electric lighting with a large event at the local school attended by 200 guests.

[17] In 1965, community contributions funded the construction of a two-kilometre concrete pathway within the village, costing five million Yugoslav dinar.

[17] That same year, another concrete path, more than two kilometres long, was built to connect Ostrovo with the nearby village of Tordinci.

In 1956, Vinkovačke Novosti highlighted the limited presence and influence of local Communist Party of Croatia members in Vukovar, Mirkovci, Ostrovo, and Cerić.

[17] During the Croatian War of Independence, Ostrovo was within the self-proclaimed Serb entity of SAO Eastern Slavonia, Baranja and Western Syrmia.

[21] The situation worsened in 1934/35, when classes moved to the Serbian Church Community Hall due to the original building’s uninhabitable state.