Lyon Peak is an mountain summit in Placer County, California, United States.
Lyon Peak is located in the Granite Chief Wilderness on land managed by Tahoe National Forest. It is situated two miles west of the crest of the Sierra Nevada mountain range, with precipitation runoff from the peak draining north into headwaters of North Fork American River, and south into headwaters of Middle Fork American River. Topographic relief is modest as the summit rises above the Middle Fork in 1.5 mile. Neighbors include Tinker Knob to the north-northeast, Granite Chief to the east-southeast, and line parent Needle Peak is east-southeast. The Palisades Tahoe ski area is four miles east of Lyon Peak. This landform's toponym has been officially adopted by the U.S. Board on Geographic Names, and has appeared in publications since at least 1915.
According to the Köppen climate classification system, Lyon Peak is located in an alpine climate zone. Most weather fronts originate in the Pacific Ocean and travel east toward the Sierra Nevada mountains. As fronts approach, they are forced upward by the peaks (orographic lift), causing them to drop their moisture in the form of rain or snowfall onto the range.