A curable silicone composition comprising: an organopolysiloxane represented by the average unit formula: (R 1 3 SiO 1/2) a (R 2 2 SiO 2/2) b (R 3 SiO 3/2) c in the formula, R 1 are the same or different, and alkyl groups having from 1 to 12 carbons, alkenyl groups having from 2 to 12 carbons, aryl groups having from 6 to 20 carbons, or aralkyl groups having from 7 to 20 carbons; R 2 are the same or different, and alkyl groups having from 1 to 12 carbons or alkenyl groups having from 2 to 12 carbons; R 3 is an alkyl group having from 1 to 12 carbons, aryl group having from 6 to 20 carbons, or an aralkyl group having from 7 to 20 carbons, provided that, in a molecule, at least 0.5 mol% of a total content of the groups represented by R 1, R 2, and R 3 are the alkenyl groups, at least one of the group represented by R 3 is the aryl group or the aralkyl group; and a, b, and c are numbers satisfying: 0.01 ≤ a ≤ 0.5, 0.4 ≤ b ≤ 0.8, 0.01 ≤ c ≤ 0.5, and a + b + c = 1; from 20 to 1,000 parts by mass, relative to 100 parts by mass of component, of an organopolysiloxane represented by the average unit formula: (R 4 3 SiO 1/2) d (R 4 2 SiO 2/2) e (R 4 SiO 3/2) f (SiO 4/2) g in the formula, R 4 are the same or different, and alkyl groups having from 1 to 12 carbons, alkenyl groups having from 2 to 12 carbons, aryl groups having from 6 to 20 carbons, or aralkyl groups having from 7 to 20 carbons, provided that, in a molecule, at least 0.5 mol% of the total content of the groups represented by R 4 are the alkenyl groups; and d, e, f, and g are numbers satisfying: 0.01 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.9, 0 f ≤ 0.9, 0 ≤ g ≤ 0.9, and d + e + f + g = 1; however, if f is a number satisfying: 0 ≤ f ≤ 0.5, g is a number satisfying: 0 < g ≤ 0.9; an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, in an amount such that a content of the silicon atom-bonded hydrogen atoms contained in this component is from 0.1 to 10 mol relative to 1 mol of the total content of the alkenyl groups contained in components and; and a hydrosilylation reaction catalyst, in an amount that accelerates curing of the composition. an organopolysiloxane represented by the average unit formula: (R 1 3 SiO 1/2) a (R 2 2 SiO 2/2) b (R 3 SiO 3/2) c in the formula, R 1 are the same or different, and alkyl groups having from 1 to 12 carbons, alkenyl groups having from 2 to 12 carbons, aryl groups having from 6 to 20 carbons, or aralkyl groups having from 7 to 20 carbons; R 2 are the same or different, and alkyl groups having from 1 to 12 carbons or alkenyl groups having from 2 to 12 carbons; R 3 is an alkyl group having from 1 to 12 carbons, aryl group having from 6 to 20 carbons, or an aralkyl group having from 7 to 20 carbons, provided that, in a molecule, at least 0.5 mol% of a total content of the groups represented by R 1, R 2, and R 3 are the alkenyl groups, at least one of the group represented by R 3 is the aryl group or the aralkyl group; and a, b, and c are numbers satisfying: 0.01 ≤ a ≤ 0.5, 0.4 ≤ b ≤ 0.8, 0.01 ≤ c ≤ 0.5, and a + b + c = 1; from 20 to 1,000 parts by mass, relative to 100 parts by mass of component, of an organopolysiloxane represented by the average unit formula: (R 4 3 SiO 1/2) d (R 4 2 SiO 2/2) e (R 4 SiO 3/2) f (SiO 4/2) g in the formula, R 4 are the same or different, and alkyl groups having from 1 to 12 carbons, alkenyl groups having from 2 to 12 carbons, aryl groups having from 6 to 20 carbons, or aralkyl groups having from 7 to 20 carbons, provided that, in a molecule, at least 0.5 mol% of the total content of the groups represented by R 4 are the alkenyl groups; and d, e, f, and g are numbers satisfying: 0.01 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.9, 0 f ≤ 0.9, 0 ≤ g ≤ 0.9, and d + e + f + g = 1; however, if f is a number satisfying: 0 ≤ f ≤ 0.5, g is a number satisfying: 0 < g ≤ 0.9; an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, in an amount such that a content of the silicon atom-bonded hydrogen atoms contained in this component is from 0.1 to 10 mol relative to 1 mol of the total content of the alkenyl groups contained in components and; and a hydrosilylation reaction catalyst, in an amount that accelerates curing of the composition.