The data set includes radiocarbon ages of sediments from the reef island Langkai, SW Sulawesi, Indonesia. The data was collected in order to reconstruct the Holocene and modern (sediment) dynamics over the past ca 6,000 years. Sediment samples were obtained from sediment cores taken by percussion drilling and hand-held (Auger) coring in May 2016 and July 2021. Laboratory analysis of the sediments and shoreline analysis were carried out between 2021 and 2023. In bulk sediment samples, a total of 20 radiocarbon ages from AMS dating were calibrated using OxCal online v4.4 (Bronk Ramsey, 2009), with the MARINE20 curve (Heaton et al., 2020) and a regional reservoir correction of deltaR= 0+-0 as suggested by Southon et al. (2002).