A multi-layer ceramic electronic component includes a multi-layer unit and a side margin. The multi-layer unit includes ceramic layers laminated in a first direction, and internal electrodes disposed between the ceramic layers, positions of end portions of the internal electrodes in a second direction orthogonal to the first direction being aligned with one another within a range of 0.5 μm in the second direction. The side margin includes a center portion in the first direction and a third direction orthogonal to the first direction and the second direction, and corner portions in the first direction and the third direction, the corner portions having a lower porosity than a porosity of the center portion, the side margin covering the multi-layer unit from the second direction.