Khentii (Mongolian: Хэнтий) is one of the 21 aimags (provinces) of Mongolia, located in the east of the country.

It is best known as the birthplace, and likely final resting place, of Temüjin, otherwise known as Genghis Khan.

The neighbouring aimags are Selenge in the northwest, Töv in the west, Govisümber in the southwest, Dornogovi in the south, Sükhbaatar in the southeast, and Dornod in the east.

The border to Töv is divided by the city of Baganuur, an administrative exclave of Ulaanbaatar.

The Onon-Balj National Park is located in the northeast of the aimag.