An aqueous coating composition comprising an acrylic resin dispersion (A) having a core/shell structure and a melamine resin (B) comprising a hydrophobic melamine resin, wherein the acrylic resin dispersion (A) is a dispersion of a solution-polymerization product of a core part preparation monomer (a-1) and a shell part preparation monomer (a-2), wherein the shell part preparation monomer (a-2) comprises an acid group-containing polymerizable monomer. The aqueous coating composition exhibits a small viscosity change and can form a coating film having a superior coating film appearance, even when the amount of the solvent contained in the aqueous coating composition is reduced due to changes in the coating environment.