Thong Lan
| King Thong Lan สมเด็จพระเจ้าทองลัน | |
|---|---|
| King of Ayutthaya | |
| King of Siam | |
| Reign | Seven days in 750 LE (1388/89 CE) |
| Predecessor | Borommarachathirat I |
| Successor | Ramesuan |
| Born | c. 735 LE (1373/74 CE) |
| Died | 750 LE (1388/89 CE) Wat Khok Phraya (in present-day Phra Nakhon Si Ayutthaya Province, Thailand) |
| House | Suphannaphum Dynasty |
| Father | Borommarachathirat I |
King Thong Lan (Thai: สมเด็จพระเจ้าทองลัน) was a king of Ayutthaya, an ancient kingdom in Thailand.
A son of Borommarachathirat I and member of the House of Suphannaphum, Thong Lan succeeded his father to the throne of Ayutthaya in 750 LE (1931 BE, 1388/89 CE) at the age of 15. Having reigned for only seven days, he was deposed and executed in a coup by Ramesuan, his relative from the House of Uthong.
Thong Lan was the first monarch of Ayutthaya to be executed.