A multilayer ceramic electronic device includes a multilayer chip having a plurality of dielectric layers and a plurality of internal electrode layers, one end of each of the plurality of internal electrode layers being exposed from the multilayer chip, an external electrode that is provided on an end face of the multilayer chip and is electrically connected to the one end of at least some of the plurality of internal electrode layers and includes a glass component, the end face being an end of the multilayer chip in a direction in which the plurality of internal electrode layers extend. The external electrode includes a crystal contacting or extending into the glass component at an interface between the external electrode and the end face of the multilayer chip. The crystal includes an element that is the same as at least one of elements included in the plurality of dielectric layers.