| Xianyou | |
| Other Name: | Sienyu; Hsienyu |
| Settlement Type: | County |
| Image Alt: | Image of Xianyou County Bus Terminal, during daytime |
| Image Map1: | ChinaFujianPutian.png |
| Map Caption1: | Putian in Fujian |
| Coordinates: | 25.362°N 118.692°W |
| Subdivision Type: | Country |
| Subdivision Name: | People's Republic of China |
| Subdivision Type1: | Province |
| Subdivision Name1: | Fujian |
| Subdivision Type2: | Prefecture-level city |
| Subdivision Name2: | Putian |
| Unit Pref: | Metric |
| Area Total Km2: | 1815 |
| Population Footnotes: | Book: zh:福建统计年鉴—2010 . zh:20-3 年末户籍统计人口数（2009年）. http://www.stats-fj.gov.cn/tongjinianjian/dz10/cn/html/2003.htm. dead. https://archive.today/20120805142309/http://www.stats-fj.gov.cn/tongjinianjian/dz10/cn/html/2003.htm. 2012-08-05. |
| Population Total: | 1066357 |
| Population As Of: | 2009 |
| Population Density Km2: | auto |
| Timezone1: | China Standard |
| Utc Offset1: | +8 |
| Postal Code Type: | Postal code |
| Postal Code: | 351200 |
| Area Code Type: | Area code |
| Area Code: | (0)594 |
| Blank Name: | Licence plates |
| Blank Info: | Chinese: 闽B |
Xianyou (; Puxian Min: Sing-iú gā̤ⁿ) is a county in the municipal region of Putian, in eastern Fujian province, People's Republic of China.
The county seat is in Licheng Subdistrict (Chinese: 鲤城街道).