A cationic electrodeposition coating composition including amino group-containing modified epoxy resin (A), blocked polyisocyanate curing agent (B), metal compound (C), and nitrogen oxide ion (E), wherein metal compound (C) is contained in an amount of 10 to 10,000 ppm calculated as metal, and nitrogen oxide ion (E) is contained in an amount of 50 to 10,000 ppm relative to the mass of the cationic electrodeposition coating composition. A coated article in which an electrodeposition coating film is formed on an untreated steel sheet exhibits excellent corrosion resistance, in particular, excellent hot salt water immersion resistance at 55° C.; and a multilayer coating film formed by a 3-coat 1-bake coating method on the electrodeposition coating film, which is formed on the untreated steel sheet, exhibits excellent corrosion resistance in a combined corrosion cycle test.