| Official Name: | Khao Yoi |
| Native Name: | เขาย้อย |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Phetchaburi |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Khao Yoi |
| Population Total: | 37697 |
| Population As Of: | 2008 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 76140 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 7602 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 13.2403°N 99.8242°W |
Khao Yoi (Thai: เขาย้อย, in Thai pronounced as /kʰǎw jɔ́ːj/) is a district (amphoe) in the northern part of Phetchaburi province, western Thailand.
The district was established in 1897 and Luang Phromsan (หลวงพรหมสาร) was assigned as the first district officer. At first named Huai Luang, the district was renamed Khao Yoi in 1903 due to the site of the district office.[1] The name of the district comes from the limestone hill called Khao Yoi which is just off Phetkasem highway. The hill contains three caves, one of which has been converted to a cave temple with a notable reclining Buddha.
Neighboring districts are (from the north clockwise) Pak Tho of Ratchaburi province, Amphawa of Samut Songkhram province, Ban Laem, Mueang Phetchaburi, Ban Lat, and Nong Ya Plong of Phetchaburi Province.
The district is divided into 10 sub-districts (tambons), which are further subdivided into 59 villages (mubans). The sub-district municipality (thesaban tambon) Khao Yoi covers parts of tambons Khao Yoi, Sa Phang, Bang Khem, and Thap Khang. There are a further seven tambon administrative organizations (TAO) responsible for the non-municipal area.
| No. | Name | Thai | Villages | Pop.[2] | |
|---|---|---|---|---|---|
| 1. | Khao Yoi | เขาย้อย | 7 | 6,873 | |
| 2. | Sa Phang | สระพัง | 4 | 3,296 | |
| 3. | Bang Khem | บางเค็ม | 6 | 3,834 | |
| 4. | Thap Khang | ทับคาง | 5 | 3,548 | |
| 5. | Nong Pla Lai | หนองปลาไหล | 5 | 2,692 | |
| 6. | Nong Prong | หนองปรง | 6 | 3,935 | |
| 7. | Nong Chumphon | หนองชุมพล | 7 | 4,605 | |
| 8. | Huai Rong | ห้วยโรง | 4 | 2,507 | |
| 9. | Huai Tha Chang | ห้วยท่าช้าง | 8 | 2,034 | |
| 10. | Nong Chumphon Nuea | หนองชุมพลเหนือ | 7 | 4,373 |