The dataset consists of six tables in CSV format, which are described below and in six attached files: Table 1: List of the 920 GNSS points of central Greece and the Peloponnese for which coordinates are provided in the ITRF2020 at the epoch 2020.0. Table 2: Velocities in the ITRF2020 of 509 points in the studied area. Table 3: ITRF2020 coordinates of 424 HMGS pillars remeasured by GNSS. Table 4: Estimated coordinates of the HMGS pillars of the investigated area at the epoch 2020.0. Table 5: List of the 1:50,000 scale HMGS maps belonging to the study area. Table 6: Coordinates calculated for each data file. The tables are in CSV format, using a comma as separator. Tables 1 and 5 contain Unicode characters (for Greek names). Content We provide a comprehensive dataset of 920 coordinates (Table 1) and 509 velocities (Table 2) for geodetic points in central Greece and the Peloponnese (Figure 1). These were observed during GNSS campaigns conducted between 1990 and 2024. The investigated region is characterised by intense tectonic deformation (Bufféral et al. 2026), either distributed in areas like southern Peloponnese or localised around fault systems such as the Corinth rift and the Katouna-Stamna and Movri fault zones. The geodetic points are organised into three main categories: permanent stations, triangulation pillars from the Greek national network (HMGS) established in the 1960s-70s, markers. The pillars of the HMGS and the markers are themselves divided into two categories, depending on whether or not they are equipped with a self-centring system. The GNSS data were processed using the GIPSY 6.4 software developed by JPL. We correct for co-seismic and post-seismic deformations in the assessment of secular velocities, using earthquake parameters derived from permanent station time series and the methodology developed in Briole et al. (2021). We show that self-centring systems significantly improve precision, reducing the average coordinate residual variability from 6.15 mm to 4.45 mm. The analysis of the 509 points with velocity determination reveals uncertainties that stabilise below 0.15 mm yr⁻¹ when the observed time period is more than twenty years. Stations with self-centring achieve 0.2 mm yr⁻¹ accuracy after twelve years of data, compared to twenty years for those without self-centring. After twenty to thirty years, campaign stations observed eight to ten times match the precision level of permanent stations. We find that the calculated velocities further validate the HELVEL crustal block model developed in Briole et al. (2021) using permanent stations only. This validation, obtained with nearly four times more points, supports the relevance of the model. We calculate a robust transformation of historical triangulation coordinates to coordinates in the ITRF2020 system at epoch 2020.0. This transformation, based on 424 coordinate pairs (Table 3), uses seven parameters and determines 1965 as the optimal reference epoch for the triangulation measurements. The root-mean-square scatter between the GNSS-based and the transformed coordinates is 0.15 m. The transformation formula is then applied to all 9,729 HMGS pillars located in the study area (Table 4). The ellipsoidal heights obtained from our GNSS measurements at 424 points (Table 4) are compared with those deduced from their levelling heights corrected from the official HG2023 grid (Paraskevas et al. 2023). The average scatter between the two determinations is -0.035 m and the standard deviation of the differences is 0.184 m. Table 6 contains the coordinates calculated for each available data file, expressed in ITRF2020 at the epoch of the observation. It covers 4,762 of the 5,187 available measurements, the remaining 425 coming from five authors cited in the accompanying documentation. The dataset, entirely referenced to ITRF2020 at epoch 2020.0, enables interoperability with previous and future geodetic work. The use of dense arrays of campaign points provides a much more detailed picture of the regional deformation field than with permanent stations alone, which is particularly important for assessing deformation at the scale of individual active faults in the investigated area. Detailed information concerning the survey campaigns, the processing of data, the application of co-seismic and post-seismic corrections, the accuracy analyses, the validation of the HELVEL model, the comparison of the GNSS coordinates of the HMGS pillars with their original coordinates, and an analysis of the differences between the levelled height and the ellipsoidal height of these pillars is provided in Briole et al. (2026): please cite this article when using this dataset. References Briole, P., Ganas, A., Elias, P. & Dimitrov, D., 2021. The GPS velocity field of the Aegean. New observations, contribution of the earthquakes, crustal block model, Geophysical Journal International, 226(1), 468-492, https://doi.org/10.1093/gji/ggab089 Briole, P., Bufféral, S., Elias, P., Avallone, A., Kamberos, K., Dimitrov, D., Marinou, A. & Ganas, A., 2026. The GNSS velocity field of Central Greece and the Peloponnese, Geophysical Journal International, under review. Bufféral, S., Briole, P., Pubellier, M. & Chamot-Rooke, N., 2026. Slip rates, diffuse deformation and interseismic loading in the Western Aegean (Greece), from GNSS velocities, Geophysical Journal International, in press. Paraskevas, M., Papadopoulos, N. & Ampatzidis, D., 2023. Geoid model determination for the Hellenic area “Hellas Geoid 2023”, Acta Geodaetica et Geophysica, 58, 345-371, https://doi.org/10.1007/s40328-023-00416-9 GNSS data Details and acknowledgements concerning the data from permanent stations can be found in Briole et al. (2021), and those concerning the campaign data in Briole et al. (2026). Disclaimer In the attached files, we endeavour to provide the most accurate coordinates, velocities and other relevant information for the geodetic points we measured between 1990 and 2024, as well as to correctly quantify the uncertainties. These products are the result of our scientific work and are not intended for commercial use or, in the case of HMGS points, to replace the official information provided by the HMGS for these points, which is the only information with legal value.