This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized radiocarbon age data of sediment core PG1975-1, retrieved in 2009 from Lake Elgene-Kyuele (lower Lena River, Yakutia, Russia) at 4.8 m water depth. The thermokarst lake Elgene-Kyuele is situated in the forest tundra and has several small outflows and one visible inflow. It lies at an elevation of ca. 147 m a.s.l. with a surface area of ca. 1.34 km2 and a maximum lake water depth of estimated 10.5 m. The 1.26 m sediment core was retrieved by a UWITEC hammer action gravity corer during the RU-Land_2009_Lena-transect expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Radiocarbon data have been analysed from bulk sediment samples in the radiocarbon laboratory at Poznan or at the Leibniz Institute in Kiel, from the total organic fraction, alkali-soluble fraction, or alkali residuals.