A dye-forming coupler of formula (I): wherein Q represents a residue that forms, together with —N—C═N—, a nitrogen-containing 6-membered ring; RA represents an aryl, heterocyclic, or —(R1)r—(R4)m group; X represents an aryl group; Y represents a hydrogen atom, or a group capable of being split-off upon a coupling reaction with an oxidized product of a developing agent: wherein, when RA represents an —(R1)r—(R4)m group, R1 represents a methylene group, a methine group, or a carbon atom; r is 1 to 30; R4 represents a substituent except for a hydrogen atom; m is 1 to 30; and the —(R1)r—(R4)m group does not represent a straight-chain alkyl group. A silver halide photographic light-sensitive material which contains at least one of the coupler. An azomethine dye compound derived from the coupler.