Provided are a photocurable ink composition including a resin which contains an amino group having one or more hydrogen atoms on a carbon atom at an α-position and having an amine value of 3.5 mmol/g to 12 mmol/g, and a radically polymerizable monomer, in which the radically polymerizable monomer contains at least one of a monofunctional radically polymerizable monomer or a bifunctional radically polymerizable monomer, a total content of the monofunctional radically polymerizable monomer and the bifunctional radically polymerizable monomer is 50% by mass or greater with respect to a total mass of the photocurable ink composition, and a content of a radically polymerizable monomer containing an acid group in the radically polymerizable monomers is 1.5 mmol or less per 100 g of the photocurable ink composition; and an image forming method performed by using the photocurable ink composition.