Tuoba, or Tabgach, are a clan of the Xianbei people of ancient China in the early centuries of the 1st millennium CE.

They establish the State of Dai from 310 to 376 CE, and the Northern Wei Dynasty from 386 to 536 CE.

Distribution of Xianbei people ranges from present day Manchuria to Mongolia, and the Tuoba clan is one of the largest clans among western Xianbei clans, ranging from present day Shanxi province and westward and northwestward.

The Tuoba clan is elevated by Chinese rulers as the leader of western Xianbei clans and its people adopt their clan name as their surname.Tabgach is the name (as attested to in the Orhun inscriptions in the Göktürk language), and most likely meant "earth-origined" (as in toprak).

The Chinese surname Yuan is later adopted by the Emperor Xiaowen of Northern Wei to replace Tuoba, and approximates the meanings of "origin" or "round" in the Chinese language.The Tuoba states of Dai and Northern Wei also claim to possess the quality of earth in the Chinese five-element analogy.Tuoba is also the ruling clan of the Western Xia Kingdom, but the king adopts the Chinese-style name Li.

Tuoba Sigong, or Li Sigong, is an ancestor of Li Yuanhao, the first king of Western Xia Kingdom.