Iguazu Falls, Iguassu Falls, or Iguacu Falls (Portuguese: Cataratas do Iguacu; Spanish: Cataratas del Iguazu) are waterfalls of the Iguazu River located on the border of the Brazilian state of Paraná and the Argentine province of Misiones. The falls divide the river into the upper and lower Iguazu.

The waterfall system consists of 275 falls along 2.7 kilometers (1.67 miles) of the Iguazu River. Some of the individual falls are up to 82 meters (269 ft) in height, though the majority are about 64 metres (210 ft). A U-shaped 82-metre-high, 150-metre-wide and 700-metre-long (490 by 2300 feet) cliff, is the most impressive of all, and marks the border between Argentina and Brazil. Two thirds of the falls are within Argentine territory.