Tsai Chin (Chinese: 蔡琴; pinyin: Cài Qín; Wade–Giles: Ts'ai4 Ch'in2; Pe̍h-ōe-jī: Chhoà Khîm) is a pop and folk singer from Taiwan.

Tsai's hits include "Forgotten Times" (《被遺忘的時光》), "Just Like Your Tenderness" (《恰似你的温柔》), "The Last Night" (《最後一夜》), "Reading You" (《讀你》) and "The Spirit of Your Eyes" (《你的眼神》).

Tsai was featured alongside Hou Hsiao-Hsien in Yang's 1985 film Taipei Story.

Tsai's song "Forgotten Times" (《被遺忘的時光》) is featured prominently in the 2002 hit Hong Kong film Infernal Affairs as a recurring element of its story line, and also in its sequels.

Besides serving to elucidate the theme of the films, the song plays an important plot function in chronologically connecting various elements of the story.