Su Tseng-chang is a Taiwanese politician who served as premier of the Republic of China (Taiwan) from 2006 to 2007 and again from 2019 to 2023. He was the chairman of the Democratic Progressive Party in 2005 and from 2012 to 2014. Su served as Chief of Staff to President Chen Shui-bian in 2004. He is currently the longest-serving Democratic Progressive premier in history.

The Democratic Progressive Party (DPP) is a Taiwanese nationalist and centre to centre-left political party in Taiwan. It is currently the major ruling party in Taiwan, controlling both the presidency and the central government, also the dominant party in the Pan-Green Coalition.