For a set of robots (or agents) moving in a graph, two properties are highly desirable: confidentiality (i.e., a message between two agents must not pass through any intermediate agent) and efficiency (i.e., messages are delivered through shortest paths). These properties can be obtained if the Geodesic Mutual Visibility ( \(\mathrm {\ensuremath {GMV}}\) ) problem is solved: oblivious robots move along the edges of the graph, without collisions, to occupy some vertices that guarantee they become pairwise geodesic mutually visible. This means there is a shortest path (i.e., a “geodesic”) between each pair of robots along which no other robots reside. In this work, we optimally solve \(\mathrm {\ensuremath {GMV}}\) on finite hexagonal grids \(G_k\) . This, in turn, requires first solving a graph combinatorial problem, i.e. determining the maximum number of mutually visible vertices in \(G_k\) .