Tun Tan Siew Sin (simplified Chinese: 陈修信; traditional Chinese: 陳修信; pinyin: Chén Xīuxìn; Pe̍h-ōe-jī: Tân Siu-sìn; 21 May 1916 – 17 March 1988) was a Malaysian politician who served as the Minister of Commerce and Industry, Minister of Finance, and 3rd President of the Malaysian Chinese Association (MCA, formerly Malayan Chinese Association), a major component party of Alliance and later Barisan Nasional (BN) coalitions. In his term as the Minister of Finance, a new Malaysian currency, Malaysian Ringgit was introduced. He is the longest-serving Minister of Finance by serving in the position for 15 years.