Khitan or Khitai may refer to:
- Khitan (circumcision), the Islamic circumcision rite
- Khitan people, an ancient nomadic people located in Mongolia and northern China
- Liao dynasty (916–1125), a dynasty of China ruled by the Khitan Yelü clan
- Northern Liao (1122–1123), a regime in northern China
- Qara Khitai (1124–1218), alternatively called the "Western Liao", successor to the Liao dynasty in northwestern China and Central Asia
- Eastern Liao (1213–1269), a regime in northeastern China
- Later Liao (1216–1219), a regime in northeastern China
- Khitan language, a now-extinct language once spoken by the Khitan people
- Khitan scripts (disambiguation), writing systems of the Khitan people, for the now-extinct Khitan language
- Khitan large script, a logographic writing system
- Khitan small script, a semi-syllabic and logographic writing system
- Cathay in many languages