An inkjet ink composition is provided that includes (Component 1-A) an N-vinyllactam, (Component 1-B) a compound represented by Formula (1), and (Component 1-C) at least one compound selected from the group consisting of a bisacylphosphine compound, a thioxanthone compound, a thiochromanone compound, and an α-aminoketone compound, the inkjet ink composition either not comprising a silicone-based surfactant or a fluorine-based surfactant or comprising a silicone-based surfactant and a fluorine-based surfactant at a total content of greater than 0 wt % but no greater than 0.03 wt % relative to the entire weight of the inkjet ink composition.There are also provided an inkjet ink composition that includes (Component 2-A) the di(meth)acrylate of a hydrocarbon diol having 5 to 10 carbons at 3 to 35 wt %, (Component 2-B) a compound represented by Formula (1) at 35 to 70 wt %, and (Component 2-C) a polymerization initiator, the inkjet ink composition having a total content of Component 2-A and Component 2-B of 50 to 90 wt %, and a surface tension at 25° C. of 33 to 37.5 mN/m.