| Kachimayu | |
| Name Etymology: | Quechua |
| Subdivision Type1: | Country |
| Subdivision Name1: | Peru |
| Subdivision Type3: | Region |
| Subdivision Name3: | Huancavelica Region |
| Mouth: | Ichhu River |
Kachimayu (Quechua kachi salt, mayu river,[1] "salt river", hispanicized spelling Cachimayo) is a river in Peru located in the Huancavelica Region, Huancavelica Province, on the border of the districts of Ascensión and Huancavelica.[2] It originates in the Chunta mountain range northwest of the peak of Antarasu near the village of Kachimayu (Cachimayo). At its confluence with the Pukapampa-Astupampa (Pucabamba-Astobamba) River, it forms the Ichhu River, which is an important affluent of the Mantaro River.