Sainyabuli, Xaignabouli, Xayaburi or Xayaboury (Lao: ໄຊຍະບູລີ) is the capital of Sainyabuli Province, Laos. It lies along Route 4 which along with Route 13 connects it to Luang Prabang, roughly 80 kilometres northeast by road and to the Thai border across the Luang Prabang Range in the southwest. A passport control point is located in the area.