| King of Thailand | |
|---|---|
| พระมหากษัตริย์ไทย | |
 Royal Standard (since 1910) | |
| Incumbent | |
.jpg) | |
| Vajiralongkorn (Rama X) since 13 October 2016 | |
| Details | |
| Style | His Majesty |
| Heir presumptive | Dipangkorn Rasmijoti |
| First monarch | Si Inthrathit |
| Formation | 1238 |
| Residence |
|
| Website | royaloffice.th |
The succession of Thai monarchs began with Si Inthrathit at the establishment of the first Thai kingdom in 1238. With brief interruptions, 55 monarchs have ruled over four successive kingdoms, the current monarch being Vajiralongkorn (Rama X) of the Chakri dynasty.