The Kuang Si Falls or Kuang Xi Falls (Lao: ນ້ຳຕົກຕາດ ກວາງຊີ), alternatively known as the Tat Kuang Si Waterfalls, is a three-tiered waterfall about 29 kilometers (18 mi) south of Luang Prabang. The waterfalls are a favorite side trip for tourists in Luang Prabang, and begin in shallow pools atop a steep hillside. These lead to the main fall with a drop of 60 meters (200 ft).

They are accessed via a trail to a left of the falls. The water flows into a turquoise blue pool before continuing downstream. The many cascades of Kuang Si are not typical of waterfalls, adding to the attractiveness.

The locals charge a nominal admission fee of 20,000 kip to visit the site, which is well maintained with walkways and bridges to guide the visitor. Most of the pools are open to swimming (although at least one is closed as being a sacred site).