This article explores the relationship between ethnic diversity and intermarriage in Vojvodina, Serbia, a highly diverse region with a history of shifting political landscapes. Unlike many studies focusing on migration, this research examines autochthonous settings from a quantitative perspective, offering insights into how diversity and intermarriage intersect locally. Findings indicate that greater ethnic diversity is generally associated with higher interethnic marriage rates within sub-regions. However, these rates have not always paralleled changes in diversity, especially during disruptions like the Yugoslav wars of the 1990s. The study reveals that declining diversity tends to reduce intermarriage by creating more homogeneous marriage markets, while intermarriages may also―albeit intermittently, under specific political circumstances, and indirectly―influence diversity trends. Results highlight small social distances and permeable ethnic boundaries among Vojvodina’s ethnic groups, though significant ethnic asymmetries remain. This study contributes to understanding the dynamics of diversity and interethnic relations, specifically through marriage, within national minority contexts.