The “Preface to the Proceedings of the 26th AGILE Conference on Geographic Information Science”, authored by Peter van Oosterom, Hendrik Ploeger, Ali Mansourian, Simon Scheider, Rob Lemmens, and Bastiaan van Loenen, is now published in GIScience Series, 4(1), Delft, The Netherlands, pp. 1-2, 2023. The 26th AGILE Conference was held at TU Delft back in June 2023.