Provided are a method of producing a compound having a colorant structure suitable for a pigment dispersant, and a pigment dispersant, a pigment composition, a pigment dispersion, and a toner each containing the compound. The production method is a method of producing a compound in which a polymer portion and a colorant portion are bonded to each other through a linking group, the method including the steps of: (a) polymerizing a vinyl-based polymerizable monomer represented by the formula (A) with a radical initiator having a protective group by living radical polymerization to provide a polymer having the protective group at a terminal thereof; (b) hydrolyzing the protective group of the polymer having the protective group at a terminal thereof obtained by the step (a) to deprotect the polymer; and (c) bonding the deprotected polymer obtained by the step (b) and a colorant to each other through a covalent bond.