A multilayer ceramic electronic component includes: a ceramic body including a dielectric layer and first and second internal electrodes stacked to be alternately exposed to one side surface and the other side surface with the dielectric layer disposed therebetween; and first and second external electrodes disposed on an external surface of the ceramic body to be connected to the first and second internal electrodes, respectively, in which the ceramic body includes an area of overlap in a thickness direction of the first and second internal electrodes, margin region, and/or cover region, and the margin region in the width direction and/or the cover region includes a phosphoric acid-based second phase.