Chikungunya (CHIK) is an emerging and reemerging infectious disease of public health importance in Indonesia. Information on the asymptomatic and true burden of CHIK virus (CHIKV) infections is limited. We assayed 1,092 healthy population samples, collected in North and South Sulawesi between 2019 and 2020, for antibodies against CHIKV. Blood samples were screened by IgM and IgG ELISAs and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay. CHIKV IgG seroprevalence in North and South Sulawesi was 53.2% and 53.9%, respectively. The overall prevalence of anti-CHIKV IgM antibody was 12.9%. Molecular testing of blood donors revealed 0.66% (2/300) were positive for CHIKV qRT-PCR. Our study provides new insights into the CHIKV endemicity situation in the eastern part of Indonesia and warrants the need for further systematic surveillance considering there is no treatment or vaccine for CHIK infection.