The August Complex was a massive wildfire that burned in the Coast Range of Northern California, in Glenn, Lake, Mendocino, Tehama, Trinity, and Shasta Counties. The complex originated as 38 separate fires started by lightning strikes on August 16–17, 2020. Four of the largest fires, the Doe, Tatham, Glade, and Hull fires, had burned together by August 30. On September 9, the Doe Fire, the main fire of the August Complex, surpassed the 2018 Mendocino Complex to become both the single-largest wildfire and the largest fire complex in recorded California history. On September 10, the combined Doe Fire also merged with the Elkhorn Fire and the Hopkins Fire, growing substantially in size. By the time it was extinguished on November 12, the August Complex fire had burned a total of 1,032,648 acres (417,898 ha), or 1,614 square miles (4,180 km2), about 1% of California's 100 million acres of land, an area larger than the state of Rhode Island.

The 2020 California wildfire season, part of the 2020 Western United States wildfire season, was a record-setting year of wildfires in California. By the end of the year, 9,917 fires had burned 4,397,809 acres (1,779,730 ha), more than 4% of the state's roughly 100 million acres of land, making 2020 the largest wildfire season recorded in California's modern history, though roughly equivalent to the pre-1800 levels which averaged around 4.4 million acres yearly and up to 12 million in peak years. California's August Complex fire has been described as the first "gigafire", burning over 1 million acres across seven counties, an area larger than the state of Rhode Island. The fires destroyed over 10,000 structures and cost over $12.079 billion in damages, including over $10 billion in property damage and $2.079 billion in fire suppression costs. The intensity of the fire season has been attributed to a combination of more than a century of poor forest management and higher temperatures resulting from climate change.