| Official Name: | Sida |
| Native Name: | สีดา |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Nakhon Ratchasima |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Sida |
| Subdivision Type3: | Subdistrict |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 24540 |
| Population As Of: | 2000 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 30430, 30120 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 3031 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 15.5425°N 102.5658°W |
Sida (Thai: สีดา, in Thai pronounced as /sǐː.dāː/) is a district (amphoe) in the northeastern part of Nakhon Ratchasima province, northeastern Thailand.
The area of Sida was separated from Bua Yai district and made a minor district on 1 July 1997.[1] On 15 May 2007, all 81 minor districts were upgraded to full districts.[2] On 24 August the upgrade became official.[3]
Neighbouring districts are (from the north clockwise): Bua Lai, Prathai, Non Daeng, and Bua Yai.
The district is divided into five subdistricts (tambons), which are further subdivided into 50 villages (mubans). Sida is also the only township (thesaban tambon) and covers parts of tambons Sida, Phon Thong, and Sam Mueang.
| 1. | Sida | สีดา | ||
| 2. | Phon Thong | โพนทอง | ||
| 3. | Non Pradu | โนนประดู่ | ||
| 4. | Sam Mueang | สามเมือง | ||
| 5. | Nong Tat Yai | หนองตาดใหญ่ |