A curable organopolysiloxane composition comprising: (A) an organopolysiloxane (a1) that contains in one molecule at least one silicon-bonded alkoxysilyl-containing group and an average of at least 0.5 alkenyl groups; or a mixture of said organopolysiloxane (a1) with an organopolysiloxane (a2) that contains in one molecule at least two alkenyl groups and that is free of the alkoxysilyl-containing groups; (B) an organopolysiloxane that contains in one molecule at least two silicon-bonded hydrogen atoms; (C) an organosilicon compound that contains in one molecule at least one silicon-bonded alkoxy group and that is free of the alkoxysilyl-containing groups; and (D) a hydrosilylation-reaction catalyst, has good adhesion to unclean aluminum die castings, PPS resins, etc., even when cured by heating at relatively low temperatures such as 100° C.