A room temperature-curable organopolysiloxane composition comprising: an alkoxysilyl-ethylene group-terminated organopolysiloxane having, at each of terminals of a molecular chain, a group represented by the following structural formula wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group as a cyclic group; R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; and n represents an integer of 0 to 10, wherein said component is at least one alkoxysilyl-ethylene group-terminated organopolysiloxane selected from an organopolysiloxane represented by the following general formula and an organopolysiloxane represented by the following general formula: wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group; R 2 represents a monovalent hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; n represents an integer of 0 to 10; 1 represents an integer of 0 to 10, and m represents an integer of 40 to 1,500; an organopolysiloxane in an amount of 10 to 250 parts by mass with respect to 100 parts by mass of said component, and represented by the following general formula wherein R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; and m represents a number at which the organopolysiloxane exhibits a viscosity of 10 to 1,000,000 mPa·s at 25°C; and a curing catalyst in an amount of 0.001 to 20 parts by mass with respect to 100 parts by mass of said component. an alkoxysilyl-ethylene group-terminated organopolysiloxane having, at each of terminals of a molecular chain, a group represented by the following structural formula wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group as a cyclic group; R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; and n represents an integer of 0 to 10, wherein said component is at least one alkoxysilyl-ethylene group-terminated organopolysiloxane selected from an organopolysiloxane represented by the following general formula and an organopolysiloxane represented by the following general formula: wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group; R 2 represents a monovalent hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; n represents an integer of 0 to 10; 1 represents an integer of 0 to 10, and m represents an integer of 40 to 1,500; an organopolysiloxane in an amount of 10 to 250 parts by mass with respect to 100 parts by mass of said component, and represented by the following general formula wherein R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; and m represents a number at which the organopolysiloxane exhibits a viscosity of 10 to 1,000,000 mPa·s at 25°C; and a curing catalyst in an amount of 0.001 to 20 parts by mass with respect to 100 parts by mass of said component.