Abaoji (872 6 September 926), posthumously known by his temple name as the Emperor Taizu of Liao, was a Khitan leader and the founding emperor of the Liao dynasty of China, ruling from 916 to 926. He had a sinicised name, Yel Yi; some sources suggest that Abaoji's family name, Yel, was adopted during his lifetime, although there is no consensus amongst historians on this point.

Abaoji was born in 872 in Southern Mongolia and had a turbulent childhood. His grandfather was killed in a conflict between tribes, and his father and uncles fled. He was hidden by his grandmother for his safety. He became khagan of the Khitans on 27 February 907, and was subsequently enthroned as emperor in 916, proclaiming his own era name. He died on 6 September 926. He was responsible for the conquest and unification of all of Inner Mongolia, northern China and southern Manchuria. Once the Khitan Empire became the Liao dynasty in 942, Abaoji was posthumously considered a Liao emperor.

The Khitan people (Khitan small script: ; Chinese: 契丹; pinyin: Qìdān) were a historical para-Mongolic nomadic people from Northeast Asia who, from the 4th century, inhabited an area corresponding to parts of modern Mongolia, Northeast China and the Russian Far East.

As a people descended from the proto-Mongols through the Xianbei, Khitans spoke the Khitan language, a Para-Mongolic language related to the Mongolic languages. During the Liao dynasty, they dominated a vast area of Siberia and Northern China. After the fall of the Liao dynasty in 1125 following the Jurchen invasion, many Khitans followed Yelü Dashi's group westward to establish the Qara Khitai or Western Liao dynasty, in Central Asia, which lasted nearly a century before falling to the Mongol Empire in 1218. Other regimes founded by the Khitans included the Northern Liao, Eastern Liao and Later Liao in China, as well as the Qutlugh-Khanid dynasty in Persia.

Using bones and teeth found in tombs, DNA analysis have determined that the Daur people are descendants of the Khitans. Another group of 100,000 descendants are found in some Blang people and Yi people in Baoshan and Ruili in southwestern Yunnan province, near Myanmar. These people with surnames of A., Mang and Jiang claim to be descendants of Khitans rather than Blang people or Yi people.