By-elections for the Tenth Legislative Yuan were held in 2023, one each on 8 January and 4 March, in Taiwan to elect 2 of the 113 members of the Legislative Yuan for the remaining term until 2024.

After the DPP's victory in Nantou II, Frida Tsai would become the first DPP legislator to serve a district in Nantou County since the 2005 constitutional amendment halving the number of legislative seats from 225 to 113.

Under the Article 73 of the Civil Servants Election And Recall Act [zh], if any positions become vacant due to resignation or election to another office, and the vacated term is longer than one year, a by-election shall be completed within three months commencing from the date of resignation.

[1] A by-election was scheduled in Taipei for 8 January 2023, as Legislative Yuan member Chiang Wan-an had resigned his seat before taking office as Mayor of Taipei.

[2] Nantou County legislator Hsu Shu-hua vacated her seat upon taking office as Nantou County magistrate on 25 December 2022, and a by-election for her seat was planned for 4 March 2023.