There are provided a compound containing a phenolic hydroxyl group, which exhibits excellent heat resistance and excellent flame retardancy in terms of a cured product thereof, a phenolic resin including the same, a curable composition and a cured product thereof, a semiconductor sealing material, and a printed circuit board. The phenolic resin contains a binuclear compound (X) represented by the following Structural Formula (I), and a trinuclear compound (Y) represented by the following Structural Formula (II) as essential components: wherein each of j and k is 1 or 2, and at least one of j and k is 2; wherein each of l, m and n is 1 or 2, and at least one of l, m, and n is 2.