A homogenized long-term dataset comprises results of the total column ozone measurements with the Dobson spectrophotometer no.84 at Belsk (51.835079°N, 20.791437°E) in central Poland. The observations were made manually at intervals depending on weather conditions. The Station is managed by the Institute of Geophysics, Polish Academy of Sciences. The data series contains the results of all intraday Dobson spectrophotometer measurements since the beginning of the ozone observations at Belsk (March, 23, 1963) up to December 31, 2019 together with the corresponding ozone air mass, cloud type over the station, and the observation codes including used UV wavelength pairs and the observation type. The data set allows to study the ozone column variability over wide time scales, from intraday oscillations to decadal trends. This is important because the ozone layer protects the Earth from harmful UV rays. The ground-based data base could also be used to validate satellite observations of the atmospheric ozone.