Disclosed herein are a semiconductor light emitting element and a backlight assembly including the same. The semiconductor light emitting element includes: a light emitting element chip including a first pad and a second pad and having an upper surface and a side surface; a wavelength conversion layer famed on the upper surface and the side surface of the light emitting element chip; a sidewall reflection part famed to be spaced apart from the side surface of the light emitting element chip; and a bottom surface reflection part famed to protrude at a lower portion of the sidewall reflection part. The sidewall reflection part and the bottom surface reflection part of the light emitting element are configured to reflect light in a direction in which the light penetrates through an upper surface of the wavelength conversion layer, the light being generated from the light emitting element chip.