| Kaiu | |
| Settlement Type: | Small borough |
| Pushpin Map: | Estonia |
| Pushpin Label Position: | top |
| Pushpin Map Caption: | Location in Estonia |
| Subdivision Type: | Country |
| Subdivision Name: |  Estonia |
| Subdivision Type1: | County |
| Subdivision Name1: | Rapla County |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Rapla Parish |
Kaiu is a small borough (Estonian: alevik) in Rapla Parish, Rapla County, Estonia.[1]
Between 1993 and 2017 (until the administrative reform of Estonian local governments), the town was the administrative center of Kaiu Parish.