To provide an ultraviolet-curable ink composition which has low viscosity, excellent adhesion, and suppressed contractility.

The ultraviolet-curable inkjet ink composition contains: about 20-70 mass%, based on the total mass of the ink composition, of a compound shown by general formula (I): CH₂=CR¹-COOR²-O-CH=CH-R³, wherein R¹ is a hydrogen atom or methyl group, R² is a C2-20 divalent organic residue, and R³ is a hydrogen atom or C1-11 univalent organic residue; and 10-20 mass%, based on the total mass of the ink composition, of at least either of a polymerizable compound that has an alicyclic structure in a molecule and a polymerizable compound that has a cyclic ether structure in a molecule.