2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121658This paper gives upper and lower bounds for the degree of the field of definition of a singular K3 surface, generalising a recent result by Shimada. We use work of Shioda-Mitani and Shioda-Inose and classical theory of complex multiplication.11 pages, 1 table; v2: incorporated referee's comments, moved CM-sectionAlgebraic GeometryNumber Theory14J28; 11G15, 11R29, 11R37, 14K22text