| Callao, Utah | |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | Utah#USA |
| Pushpin Label: | Callao |
| Pushpin Label Position: | right |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Utah |
| Subdivision Type2: | County |
| Subdivision Name2: | Juab |
| Established Title: | Settled |
| Established Date: | 1860 |
| Named For: | Callao |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Elevation Ft: | 4337 |
| Coordinates: | 39.8978°N -113.7086°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 84034 |
| Area Code: | 435 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 1437516 |
Callao is a community in northern Snake Valley, along the border of Juab and Tooele counties, Utah, United States.
The community was part of the original Pony Express overland route, and was first called Willow Springs in 1860. E. W. Tripp, his wife, and their son were the first to establish residence there, in 1870. In 1895 it was decided that Willow Springs was too common a name, and a new name would be chosen. The name Callao was chosen because of a resemblance to Callao, Peru, suggested by an old grizzled 1890s prospector in the region who was working out of Gold Hill to the north.[1]
According to the Köppen Climate Classification system, Callao has a semi-arid climate, abbreviated "BSk" on climate maps.[2]