Provided are: an antistatic agent and an antistatic agent composition which are capable of providing excellent antistatic effect in a small amount and have sufficient persistence and wiping resistance without impairing the intrinsic physical properties of a resin; and an antistatic resin composition and a molded article using the same.The antistatic agent includes a polymer compound (E) having a structure in which a diol, an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, a compound (B) which comprises at least one group represented by the following Formula (1) and has hydroxyl groups at both ends, and a polyhydric alcohol (D) having three or more hydroxyl groups are bound via ester bonds: —CH2—CH2—O—  (1).