Resist composition, resist pattern formation method, compound, and polymer compound

A resist composition which generates an acid upon light exposure and whose solubility in a developing solution is changed by an action of the acid, the resist composition comprising:

• a resin component (A1) whose solubility in a developing solution is changed by the action of the acid,
• wherein the resin component (A1) has a constitutional unit (a0) derived from a compound represented by General Formula (a0-m),
• wherein W0 represents a polymerizable group-containing group, R0 represents a hydrocarbon group, an acyl group, an alkoxyalkyl group, or a hydrogen atom, L01 represents a divalent linking group or a single bond, Rar represents an aromatic ring to which an iodine atom is bonded as a substituent, a substituent other than the iodine atom may be bonded to the aromatic ring, L02 represents a divalent linking group, n0 represents an integer of 1 or more, as long as an atomic valence allows, m represents an integer of 1 or more, and (Mm+)n0/m represents a counter cation.