| Official Name: | Si Wichai |
| Native Name: | ศรีวิชัย |
| Settlement Type: | Subdistrict |
| Pushpin Map: | Thailand |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type2: | Province |
| Subdivision Name2: | Lamphun |
| Subdivision Type3: | District |
| Subdivision Name3: | Li District |
| Population As Of: | 2005 |
| Population Total: | 7869 |
| Timezone: | ICT |
| Utc Offset: | +7 |
Si Wichai (th|ศรีวิชัย, pronounced as /th/) is a village and tambon (subdistrict) of Li District, in Lamphun Province, Thailand.[1] In 2005 it had a population of 7869 people. The tambon contains 13 villages.