Tsai Hong-tu (Chinese: 蔡宏圖; pinyin: Cài Hóngtú; Wade–Giles: Tsai4 Hung2-tu2; born 1 August 1952) is a Taiwanese businessman and banker who currently chairs Cathay Financial Holdings.

Tsai was born in Zhunan, Miaoli County and grew up in Taipei.

The son of billionaire Tsai Wan-lin, he earned a Bachelor of Laws (LL.B.)

The Tsai family also controls Cathay Real Estate, a Taiwanese property developer.

[1] In the same year, Forbes also listed Tsai as one of the world's most altruistic individuals for donating US$3 million toward Typhoon Morakot relief and for giving US$7.8 million to National Taiwan University's law school in 2003.