Provided are: a novel triepoxy compound capable of forming, through polymerization, a cured article having excellent heat resistance; a production method thereof; a curable composition including the triepoxy compound; and a cured article obtained by curing the curable composition.The triepoxy compound according to the present invention is represented by Formula (1). The triepoxy compound represented by Formula (1) may be obtained typically by oxidizing a compound represented by Formula (2) with an oxidizing agent. In Formulae (1) and (2), R1 to R2° are the same as or different from one another and each represent hydrogen atom, methyl group, or ethyl group. Formulae (1) and (2) are expressed as follows: