Provided is a curable composition that is rapidly cured to form a cured product. The cured product resists yellowing, successfully maintains excellent transparency over a long time even in a high-temperature environment, and is advantageously usable as or in a wafer-level lens. The curable composition according to the present invention includes a cycloaliphatic epoxide (A), a siloxane compound (B), and a curing agent (C). The cycloaliphatic epoxide (A) is represented by Formula (1). The siloxane compound (B) contains two or more glycidyl groups per molecule. In the formula, X is selected from a single bond and a linkage group.