This open access volume contains the proceedings of the X Hotine-Marussi Symposium on Mathematical Geodesy which was held from 13 to 17 June 2022 at the Politecnico di Milano, Milan, Italy. Since 2006 the series of the Hotine-Marussi Symposia has been under the responsibility of the Inter-Commission Committee on Theory (ICCT) within the International Association of Geodesy (IAG). The ICCT organized the last five Hotine-Marussi Symposia held in Wuhan (2006), Rome (2009, 2013 and 2018), and Milan (2022). The overall goal of the ICCT and Hotine-Marussi Symposia has always been to advance geodetic theory which is indeed documented by the 22 research articles published in these proceedings. The jubilee X Hotine-Marussi Symposium was organized in 10 topical sessions covering all parts of geodetic theory including reference frames, gravity field modelling, adjustment theory, height systems, time series analysis, or advanced numerical methods. In total, 60 participants attended the Symposium who delivered 62 oral and 18 poster presentations. During a special session, five invited speakers discussed two basic concepts of physical geodesy ¿ geoid and quasigeoid.
