| Official Name: | Xianxi Township 線西鄉 |
| Other Name: | Siansi; Hsienhsi |
| Subdivision Type: | Location |
| Area Total Km2: | 18 |
| Population As Of: | January 2023 |
| Population Total: | 16310 |
| Population Density Km2: | auto |
Xianxi Township or Siansi Township (Wade-giles: Hsianhsi) is a rural township in Changhua County, Taiwan with 16,310 residents (January 2023). With an area of 18.1 square kilometres, it is the smallest township in the county.
The township comprises eight villages: Dexing, Dingli, Dingzhuang, Gounei, Wenzi, Xiali, Xianxi and Yupu.[1]