To provide a curable silicone rubber composition which gives a silicone rubber excellent in flame retardance without affecting the properties of the yielded silicone rubber.

The flame-retardant silicone rubber composition contains a blowing agent which generates a gas in an amount of ≥250 ml/g by heat decomposition. The flame-retardant silicone rubber composition is obtained by incorporating the blowing agent into a condensation curable organopolysiloxane composition comprising (A) an organopolysiloxane having at least two hydroxy groups bonded to silicon atoms in the molecule, (B) an organosilicon compound represented by the formula: RaSiX4-a (wherein R is independently a non-substituted or substituted 1-10C monovalent hydrocarbon group: X is independently a ketoxime group, an alkoxy group or a 1-methylvinyloxy group; and a is 0, 1 or 2) and/or its partial hydrolysis condensate, and (C) a curing catalyst.