A group-III nitride semiconductor light emitting element includes a semiconductor layer that includes a light emitting layer, a p-type semiconductor layer and an n-type semiconductor layer, a p-contact electrode that is in contact with the p-type semiconductor layer, an n-contact electrode that is in contact with the n-type semiconductor layer, and a support substrate that supports the semiconductor layer. The p-contact electrode and the n-contact electrode are disposed at a position between the semiconductor layer and the support substrate. In a case where the p-contact electrode and the n-contact electrode are orthogonally projected on a plate surface of the support substrate, the p-contact electrode and the n-contact electrode are formed in a shape in which the orthogonally projected p-contact electrode and the orthogonally projected n-contact electrode are not overlapped with each other.