Chiang was born Chang Wan-an (Chinese: 章萬安; pinyin: Zhāng Wàn'ān) on 26 December 1978 in Taipei, Taiwan.

[1][2] He is the only son of minister Chiang Hsiao-yen and Helen Huang (黃美倫; Huáng Měilún) and has two elder sisters.

[4] His contested familial relationship with the Chinese leader has been controversial due to Chiang Kai-shek's divisive legacy as either a symbol of anti-communism or dictatorship.

Because he graduated at the top of his high school class, he was automatically admitted to National Chengchi University, where he double majored in international relations and law.

[12] Chiang faced Lo Shu-lei in the first round of the Kuomintang party primary for the legislative elections in April 2015.

[15] The Taipei District Prosecutor's Office ended an investigation of vote-buying accusations against Chiang in March, but did not charge him with wrongdoing.

[16] In January 2018, Chiang stated that he would not seek to represent the Kuomintang in the Taipei mayoral election scheduled for November.

[17] Chiang ran for reelection in 2020, defeating his closest opponent, Democratic Progressive Party candidate Enoch Wu, by six percent of votes, 51–45%.

[26] Chiang met his future wife, Shih Fang-hsuan (石舫亘), while both were students at National Chengchi University.