| Official Name: | Ratchasan |
| Native Name: | ราชสาส์น |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Chachoengsao |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Bang Kha |
| Subdivision Type3: | Subdistrict |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 12,809 |
| Population As Of: | 2017 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 24120 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 2407 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 13.7822°N 101.2817°W |
Ratchasan (Thai: ราชสาส์น, in Thai pronounced as /râːt.t͡ɕʰā.sǎːn/) is a district (amphoe) in the central part of Chachoengsao province, central Thailand.
The area of Ratchasan was separated from Phanom Sarakham district and became a minor district (king amphoe) on 16 February 1977.[1] It was upgraded to a full district on 4 July 1994.[2]
Neighboring districts are (from the east clockwise): Phanom Sarakham, Plaeng Yao, and Bang Khla of Chachoengsao Province; and Ban Sang of Prachinburi province.
The important water resource is the Khlong Tha Lat.
Ratchasan is divided into three sub-districts (tambons), which are further subdivided into 31 administrative villages (mubans).
| No. | Name | Thai | Villages | Pop.[3] | |
|---|---|---|---|---|---|
| 1. | Bang Kha | Thai: บางคา | 6 | 2,132 | |
| 2. | Mueang Mai | Thai: เมืองใหม่ | 9 | 3,146 | |
| 3. | Dong Noi | Thai: ดงน้อย | 16 | 7,531 |
There are three sub-district administrative organizations (SAO) in the district:
Palmyrum is a local important industrial crop. Ratchasan is famous for its palm sap.