The Yellowstone fires of 1988 formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. No less than 3123 km2 was destroyed or severely affected by the wildfires, which is 36 % of the entire park surface. Starting as many smaller individual fires during the extreme drought of the summer of 1988, the flames quickly spread out of control. With the increasing winds and drought the small fires combined into one large conflagration, which burned for several months. Only the arrival of cool and moist weather in the late autumn brought the fires to an end.

Before the late 1960s, fires were generally believed to be detrimental for parks and forests, and management policies were aimed at suppressing fires as quickly as possible. However, as the beneficial ecological role of fire became better understood in the decades before 1988, a policy was adopted of allowing natural fires to burn under controlled conditions, which proved highly successful in reducing the area lost annually to wildfires. Moreover, the burnt areas often add a new a dynamic  to the ecosystem and the regeneration of the forest often soon creates lush dense vegetation patches.  

However, in 1988, Yellowstone was overdue for an extremely large and devastating fire. The fires burned discontinuously, leaping from one patch to another, leaving intervening areas untouched. Large firestorms swept through some regions, burning everything in their paths. Tens of millions of trees and countless plants were killed by the wildfires, and some regions were left looking blackened and dead. However, more than half of the affected areas were burned by ground fires, which did less damage to hardier tree species. But as usual, not long after the fires ended, plant and tree species quickly reestablished themselves, and natural plant regeneration has been highly successful. The Moose is one of the few mammals which seem to have been strongly affected by the fires, and of which the population is still much lower than it used to be before 1988.