Provided are: a compound containing a phenolic hydroxy group, which has excellent heat resistance; a composition for resists, which has excellent thermal decomposition resistance, optical sensitivity and resolution; and a composition for resist underlayer films, which has excellent thermal decomposition resistance and dry etching resistance. A compound containing a phenolic hydroxy group, said compound being characterized by having a molecular structure represented by structural formula (1) (wherein R1 represents a hydrogen atom, an alkyl group or an aryl group; n represents an integer of 2 to 10; R2 represents any one of an alkyl group, an alkoxy group, an aryl group, an aralkyl group and a halogen atom; and m represents an integer of 0 to 4, wherein when m is 2 or greater, multiple R2's may be the same as or different from each other and each of the multiple R2's may be bound to either one of two aromatic rings in a naphthylene backbone).