The Han languages (Korean: 한어; Hanja: 韓語) or Samhan languages (삼한어; 三韓語) were the languages of the Samhan ('three Han') of ancient southern Korea, the confederacies of Mahan, Byeonhan and Jinhan. They are mentioned in surveys of the peninsula in the 3rd century found in Chinese histories, which also contain lists of placenames, but are otherwise unattested. Based on the description in these histories of cultural differences between the Samhan and the kingdoms of the north of the peninsula, Ki-Moon Lee assigned their languages to Han and Puyŏ groups respectively. There is no consensus about the relationships between these languages and the languages of later kingdoms.

The Samhan are known from Chinese histories. Chapter 30 of the Records of the Three Kingdoms (late 3rd century) and Chapter 85 of the Book of the Later Han (5th century) contain parallel accounts, apparently based on a common source, of peoples neighbouring the Four Commanderies of Han in northern Korea.

The Chinese histories describe the Samhan as culturally significantly different from the peoples of the northern part of the peninsula. They state that Jinhan had a different language from Mahan, listing some Jinhan words said to be shared with the Chinese state of Qin, from which the Jinhan claimed to be refugees (a claim discounted by most historians). The two accounts differ on the relationship between the languages of Byeonhan and Jinhan, with the Records of the Three Kingdoms describing them as similar, but the Book of the Later Han referring to differences.

The Records of the Three Kingdoms also gives phonographic transcriptions in Chinese characters of names of settlements, 54 in Mahan and 12 each in Byeonhan and Jinhan. Some of these names appear to include suffixes:

The Gwanggaeto Stele (414) lists Goguryeo and Han villages, without subdividing the latter.

In the 4th century, Baekje, the Gaya confederacy and Silla arose from Mahan, Byeonhan and Jinhan respectively. Linguistic evidence from these states is sparse and, being recorded in Chinese characters, difficult to interpret. Most of these materials come from Silla, whose language is generally believed to be ancestral to all extant Korean varieties as a result of the Sillan unification of most of the peninsula in the late 7th century.

Apart from placenames, whose interpretation is controversial, data on the Baekje language is extremely sparse:

A single word is directly attributed to the Gaya language in the Samguk sagi (1145). It is the word for 'gate', and appears to resemble the Old Japanese word for 'gate'.