While by discussing notions of spatial representation, boundaries, and geographical entities Chaps. 3– 5 have been essentially speculative, this chapter aims to analyze geo-ontologies as an IT/computer application of the theoretical investigation presented so far. Section 6.1 explores the emergence of geo-ontologies from the spatial turn and sketches their general as well as specific goals. Sections 6.2 and 6.3 are, respectively, dedicated to show the most relevant examples of taxonomies derived from the IT domain and to underline the absence of a classification suitable for spreading geo-ontologies in the geographical debate. Finally, Sect. 6.4 is concerned with outlining a taxonomy grounded on the distinction between spatial, physical, and human geo-ontologies. The idea behind this taxonomy is to relate geo-ontologies to the geographical debate which, in turn, could improve the conceptualizations of such ontologies.