Iztaccíhuatl (alternative spellings include Ixtaccíhuatl, or either variant spelled without the accent) (Nahuatl pronunciation: [istakˈsiwatɬ] or, as spelled with the x, [iʃtakˈsiwatɬ]), is a 5,230 m (17,160 ft) mountain in Mexico. It is the nation's third highest, after Pico de Orizaba 5,636 m (18,491 ft) and Popocatépetl 5,426 m (17,802 ft).

The name "Iztaccíhuatl" is Nahuatl for "White woman", reflecting the four individual snow-capped peaks which depict the head, chest, knees and feet of a sleeping female when seen from east or west.

Iztaccíhuatl lies to the north of Popocatépetl, to which it is connected by the high altitude Paso de Cortés. Depending on atmospheric conditions the dormant volcano is visible much of the year from Mexico City some 70 km (43 mi) to the northwest.

The first recorded ascent was made in 1889, though archaeological evidence suggests the Aztecs and previous cultures climbed it previously. It is the lowest peak containing permanent snow and glaciers in Mexico.

The summit ridge of the massive 450 km³ (110 cu mi) volcano is a series of overlapping cones constructed along a NNW-SSE line to the south of the Pleistocene Llano Grande caldera. Andesitic and dacitic Pleistocene and Holocene volcanism has taken place from vents at or near the summit. Areas near the El Pecho summit vent are covered in flows and tuff beds post-dating glaciation approximately 11 ka (thousand years ago). The most recent vents are located at El Pecho and a depression at 5,100 m (16,700 ft) along the summit ridge midway between that summit and Los Pies.