The curable and foamable organopolysiloxane composition comprises three different organopolysiloxanes, of which (A) the first is an .alpha.,.omega.-divinyl dimethyl polysiloxane, (B) the second is an organopolysiloxane having, in a molecule, at least three silicon-bonded hydroxy groups and (C) the third is an organohydrogenpolysiloxane having, in a molecule, at least two silicon-bonded hydrogen atoms, along with a platinum catalyst. The platinum-catalyzed curing and foaming reactions proceed in two ways of, one, the hydrosilation between the vinyl groups in (A) and the silicon-bonded hydrogen atoms in (C) and, the other, by the dehydrogenation between the silanol groups in (B) and the silicon-bonded hydrogen atoms in (C). The composition gives a cured and foamed silicone rubber body having excellent mechanical properties with a good cell structure by standing at room temperature or by heating up to 70.degree. C.