| Official Name: | Lom Kao |
| Native Name: | หล่มเก่า |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Phetchabun |
| Subdivision Type2: | Seat |
| Subdivision Type3: | Tambon |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 67101 |
| Population As Of: | 2015 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 67120 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 6704 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 16.8856°N 101.2294°W |
Lom Kao (in Thai pronounced as /lòm kàw/) is the northernmost district (amphoe) of Phetchabun province, northern Thailand.
The first record of Mueang Lom is found in Ram Khamhaeng the Great's stone pillar. In the Rattanakosin era, the area was populated by a large community of Lao people from Vientiane. The population grew due to further immigration from Luang Prabang and Vientiane, so the governor led some people to establish a new town near the Pa Sak River, now in the Lom Sak district.
Neighboring districts are (from the north clockwise) Dan Sai and Phu Ruea of Loei province and Nam Nao, Lom Sak, and Khao Kho of Phetchabun Province.
Lom Kao district is divided into nine sub-districts (tambons), which are further subdivided into 99 administrative villages (mubans).
| No. | Name | Thai | Villages | Pop.[1] | |
|---|---|---|---|---|---|
| 1. | Lom Kao | Thai: หล่มเก่า | 13 | 11,959 | |
| 2. | Na Sam | Thai: นาซำ | 10 | 7,345 | |
| 3. | Hin Hao | Thai: หินฮาว | 13 | 7,506 | |
| 4. | Ban Noen | Thai: บ้านเนิน | 8 | 5,254 | |
| 5. | Sila | Thai: ศิลา | 16 | 10,066 | |
| 6. | Na Saeng | Thai: นาแซง | 7 | 3,921 | |
| 7. | Wang Ban | Thai: วังบาล | 17 | 11,649 | |
| 8. | Na Ko | Thai: นาเกาะ | 6 | 2,642 | |
| 9. | Tat Kloi | Thai: ตาดกลอย | 9 | 6,759 |
There is one sub-district municipality (thesaban tambon) in the district:
There are nine sub-district administrative organizations (SAO) in the district: