There are provided a dielectric composition and a multilayer ceramic electronic component manufactured using the same, the dielectric composition including a dielectric grain having a perovskite structure represented by ABO3, wherein the dielectric grain has a core-shell structure in which a content of an additive in a shell is 15% or less, based on an average content of the additive distributed throughout the dielectric grain, so that the multilayer ceramic electronic component manufactured using the dielectric composition can have excellent reliability and secure a high dielectric constant.