Chagas disease, caused by Trypanosoma cruzi, remains a neglected tropical disease of public health importance in Latin America, particularly in rural areas. In Floriano, Piauí, Brazil, data on infection prevalence are limited. This cross-sectional population-based study assessed the seroprevalence of T. cruzi infection and analyzed sociodemographic factors associated with seropositivity among residents of 41 rural communities in Floriano. A total of 1212 individuals aged over six years were examined, revealing a seroprevalence of 3.2% (39/1212), with positive cases detected in 17 communities. Infection was significantly associated with older age (≥60 years; p < 0.0001), low educational level (p = 0.0184), retirement status (p < 0.0001), and low income (p = 0.0505). Logistic regression confirmed age as the strongest determinant of infection (OR = 7.647; 95% CI: 3.741–18.61; p < 0.0001), while higher monthly income showed a negative association with infection (OR = 0.17; 95% CI: 0.01–0.82; p = 0.086), indicating a trend toward significance. These findings highlight the persistence of T. cruzi infection in rural Floriano, predominantly among elderly individuals living in poverty. The identification of previously undiagnosed chronic cases reinforces the urgent need for targeted epidemiological surveillance, early diagnosis, and community-based health education to strengthen local control and prevention strategies.