Tridé Songtsen , nicknamed Sadnalegs , was the 39th King (''Tsenpo'') of Tibet from 800 to 815. He was the third and youngest son of Trisong Detsen. He reigned between the disputed king, Muné Tsenpo, and the 40th king, Ralpachen, making the dates of his reign from 800 to 815.

After Trisong Detsen retired to live at Zungkar,