There is provided a multilayer ceramic electronic component including: a ceramic body in which internal electrodes containing a first electrode material and dielectric layers are alternately disposed; external electrodes provided on outer surfaces of the ceramic body and containing a second electrode material; and diffusion parts each disposed to be connected to one end of the internal electrode and the external electrode and containing the first electrode material and the second electrode material mixed with each other, wherein the diffusion part includes an internal diffusion portion disposed within the ceramic body and an external diffusion portion protruding outside of the ceramic body.