This paper presents three related findings on regional decentralization. We use an original dataset collected in Uganda to establish, for the first time in a developing country context, that individuals have meaningful preferences over the degree of regional decentralization they desire, ranging from centralism to secessionism. Second, multilevel models suggest that a small share of this variation is explained at the district and ethnic group levels. The preference for regional decentralization monotonically increases with an ethnic group or district's average ethnic attachment. However, the relationship with an ethnic group or district's income is U-shaped: both the richest and the poorest groups desire more regionalism, reconciling interest and identity-based explanations for regionalism. Finally, we show that higher individual ethnic attachment increases preferences for regionalism using fixed effects and a new matching method. Abstract This paper presents three related findings on regional decentralization. We use an original dataset collected in Uganda to establish, for the first time in a developing country context, that individuals have meaningful preferences over the degree of regional decentralization they desire, ranging from centralism to secessionism. Second, multilevel models suggest that a small share of this variation is explained at the district and ethnic group levels. The preference for regional decentralization monotonically increases with an ethnic group or district's average ethnic attachment. However, the relationship with an ethnic group or district's income is U-shaped: both the richest and the poorest groups desire more regionalism, reconciling interest and identity-based explanations for regionalism. Finally, we show that higher individual ethnic attachment increases preferences for regionalism using fixed effects and a new matching method.