A curable silicone composition containing an organopolysiloxane that contains in one molecule at least one epoxy-containing organic group, has a polystyrene-referenced weight-average molecular weight at least 500, and is expressed by the following general unit formula: (RSiO3/2)x[R1aSiO(4-a)/2]y (where R represents a cycloalkyl group, and R1 represents hydrogen atom or a univalent organic group, except for an aromatic group and a cycloalkyl group, at least one R1 in one molecule being an epoxy-containing univalent organic group, and where the following condition is observed: 0 0; y>0; and x+y=1).