The Sharingan is the Kekkei Genkai of the Uchiha Clan. It is awakened when an Uchiha experiences an intense emotional overdrive. However, many of the Non-Uchiha have managed to get their hands on this Dōjutsu as well.
Here are all 6 Non-Uchiha who possessed the Sharingan.
6. Danzo Shimura
Danzo Shimura always kept one of his eyes concealed. The reason for that was a stolen Sharingan. He also managed to steal Shisui’s Mangekyō Sharingan. Orochimaru also did a couple of experiments on him. He possessed a prosthetic arm made from Hashirama’s cells, with 10 Sharingan embedded in it.