Resist composition, method for forming resist pattern, compound, and acid diffusion control agent

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

• a resin component (A1) whose solubility in a developing solution is changed under action of an acid;
• and
• an acid diffusion control agent component (D) which controls an acid generated upon exposure to light,
• wherein the acid diffusion control agent component (D) contains a photodecomposable base (D0) represented by General Formula (d0) that generates a carboxylic acid having a pKa of 0.50 or more as a generated acid,
• wherein Rm represents a hydrogen atom or a hydroxy group, X0 represents a bromine atom or an iodine atom, nb1 represents an integer in a range of 1 to 4, Yd0 represents a divalent linking group or a single bond, Rb1 represents a fluorine atom or a fluorinated alkyl group, p01 represents an integer in a range of 1 to 5, Rb2 and Rb3 each independently represent a hydrocarbon group which may have a substituent, Rb2 and Rb3 may be bonded to each other to form a ring together with a sulfur atom in the formula, Rb2 and Rb3 may form a condensed ring together with a benzene ring and a sulfur atom in the formula, at least one Rb1 is bonded to an ortho-position or a meta-position of the benzene ring, the number of all fluorine atoms contained in —F and/or —CFRx1Rx2, which are bonded to an aromatic ring bonded to the sulfur atom in the formula is 3 or more, and Rx1 and Rx2 each independently represent a fluorine atom or a hydrogen atom.