A monolithic ceramic electronic component includes a component body and outer electrodes. The component body includes a plurality of stacked ceramic layers and a plurality of inner electrodes which extend between the ceramic layers, which contain Ni, and which include exposed ends exposed on predetermined surfaces of the component body. The outer electrodes are electrically connected to the exposed ends of the inner electrodes and are formed on the predetermined surfaces of the component body by plating. The inner electrodes include Mg—Ni coexistence regions where Mg and Ni coexist.