A curable and hygroscopic resin composition for sealing electronic devices, having at least a (meth)acrylate oligomer (a) having the number-average molecular weight of 1,500 to 5,000, a low molecular weight (meth)acrylate (b) having an average molecular weight of 170 to 500, a moisture-reactive organometallic compound (c), and a polymerization initiator (d), wherein the (meth)acrylate oligomer (a) and the low molecular weight (meth)acrylate (b) are multifunctional (meth)acrylates in which the number of (meth)acryloyl groups is from 1.5 to 3 in one molecule of each of the (meth)acrylate oligomer (a) and the low molecular weight (meth)acrylate (b); a sealing resin; and an electronic device.