| Type: | town |
| Hay Valley | |
| State: | sa |
| Coordinates: | -35.0078°N 138.9047°W |
| Lga: | District Council of Mount Barker |
| Lga2: | Adelaide Hills Council |
| Postcode: | 5252 |
| Stategov: | Kavel |
| Fedgov: | Mayo |
| Dist1: | 11 |
| Location1: | Mount Barker |
| Dist2: | 37 |
| Location2: | Adelaide |
| Near-Nw: | Oakbank |
| Near-N: | Woodside |
| Near-Ne: | Brukunga |
| Near-E: | Brukunga |
| Near-Se: | Nairne |
| Near-S: | Nairne |
| Near-Sw: | Mount Barker Junction Littlehampton |
| Near-W: | Balhannah |
Hay Valley is a small locality in South Australia, north of Nairne.[1] It overlies the geographical feature of the same name and was originally established as a named subsection within the Hundred of Kanmantoo.[1] [2] In 2016 the population was 25.