Provided is a novel curable composition with which it is possible to form a cured film expected to be useful in optical films such as anti-reflection films, the curable composition utilizing living radical polymerization of a polymer into which a RAFT agent is introduced. A curable composition including component (A) and component (B), and including 1-99 wt% of component (A) relative to the total weight of the two components. Component (A): polymer in which end polymerization-active groups are protected by radical-cleavable covalent bonds. Component (B): compound having at least one (meth)acryloyl group in the molecule.