The present invention relates to a curable composition including: (a) at least one compound having at least one (meth)acrylic functional group in the molecule thereof, which is selected from a (meth)acrylic monomer and a (meth)acrylic oligomer; (b) an organic peroxide; (c) an o-benzoic sulfimide; and (d) an oxazoline compound, in which the component (d) is contained in an amount of 0.005 to 10 parts by mass based on 100 parts by weight of the component (a).