| Official Name: | Sunnyside, Castro County, Texas |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | Texas#USA |
| Pushpin Label: | Sunnyside |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Texas |
| Subdivision Type2: | County |
| Subdivision Name2: | Castro |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 3734 |
| Coordinates: | 34.3481°N -102.3036°W |
| Area Code: | 806 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 1380630 |
Sunnyside is an unincorporated community in Castro County, Texas, United States. According to the Handbook of Texas, the community had an estimated population of 80 in 2000.
Sunnyside is located on U.S. Route 385, 15miles south of Dimmitt in Castro County.
Today, the community is served by the Dimmitt Independent School District and the Springlake-Earth Independent School District.