Mount Haeckel is a 13,424-foot (4,092 m) mountain summit located on the crest of the Sierra Nevada mountain range in northern California, United States. It is situated on the shared boundary of Kings Canyon National Park with John Muir Wilderness, and along the common border of Fresno County with Inyo County. It is 21.5 miles (34.6 km) west of the community of Big Pine, 1.27 miles (2.04 km) south-southeast of Mount Darwin, and one mile north-northeast of Mount Fiske, which is the nearest higher neighbor. Mount Haeckel ranks as the 71st highest summit in California.