Sino-Japanese vocabulary or kango (Japanese: 漢語) refers to that portion of the Japanese vocabulary that originated in Chinese or has been created from elements borrowed from Chinese. Some grammatical structures and sentence patterns can also be identified as Sino-Japanese. Sino-Japanese vocabulary is referred to in Japanese as kango (漢語), meaning 'Chinese words'. Kango is one of three broad categories into which the Japanese vocabulary is divided. The others are native Japanese vocabulary (yamato kotoba) and borrowings from other, mainly Western languages (gairaigo). It is estimated that approximately 60% of the words contained in a modern Japanese dictionary are kango, and they comprise about 18% of words used in speech.

Kango, the use of Chinese-derived words in Japanese, is to be distinguished from kanbun, which is actual Chinese written by Japanese in Japan. Both kango in modern Japanese and classical kanbun have Sino-xenic linguistic and phonetic elements also found in Korean and Vietnamese: that is, they are "Sino-foreign," not purely Chinese.