A multilayer ceramic electronic component includes a multilayer body and external electrodes provided on opposing end surfaces of the multilayer body. Each external electrode includes an underlying electrode layer including metal components and ceramic components, and plating layers on the underlying electrode layer. A metal of the plating layer on the underlying electrode layer diffuses into the underlying electrode layer to extend from a surface layer of the underlying electrode layer to an interface of the multilayer body, and exists at an interface where the metal components included in the underlying electrode layer are in contact with each other, an interface where the metal component and the ceramic component included in the underlying electrode layer are in contact with each other, and an interface between the metal component included in the underlying electrode layer and the multilayer body.