Provided is a curable composition having excellent workability and being capable of forming a cured product having super heat resistance by curing. The curable composition of the present disclosure includes a curable compound represented by Formula (1) below and a radical polymerization initiator. In the following formula, R1 and R2 each represent a curable functional group, and D1 and D2 each represent a single bond or a linking group. L represents a divalent group having a repeating unit containing a structure represented by Formula (I) below and a structure represented by Formula (II) below. Ar1 to A3 each represent an arylene group or a group in which two or more arylene groups are bonded via a single bond or a linking group. X represents —CO—, —S—, or —SO2—, and Y represents —S—, —SO2—, —O—, —CO—, —COO—, or —CONH—. n represents an integer of 0 or greater.