The Black Númenóreans were those folk of Númenórean descent who chose to follow Sauron.

They lived in Umbar (on the southeast coast of Middle-earth) and for many years attacked coastal villages. The Black Númenóreans held a friendship with Sauron the Great and it was said that three of the Númenórean Lords were given Rings of Power and later became Ringwraiths. Two others named Herumor and Fuinur became lords of the Haradrim.

In the year TA 1050 they were driven out of Umbar by Hyarmendacil I of Gondor and became nomadic, later merging with the Haradrim and the Corsairs of Umbar or living in Mordor and Morgul. One of these Númenóreans was later favored so highly by Sauron as to become the spokesman of the Dark Lord, or The Mouth of Sauron. However, when Sauron fell at the end of the Third Age, all of his gifts and powers given to the Black Númenóreans fell as well, leading to the end of the race.