The Great Savannah Fire of 1820 destroys over 400 buildings in Savannah, Georgia.

On January 11, 1820, a conflagration affected the city of Savannah, Georgia, United States, burning down almost 500 buildings and causing roughly $4 million in damages. It was the most severe fire in the city's history and one of the most damaging in the country at that time.

Savannah is the oldest city in the U.S. state of Georgia and the county seat of Chatham County. Established in 1733 on the Savannah River, the city was the capital of the colonial Province of Georgia and later the first state capital of Georgia. A strategic port city in the American Revolution and during the American Civil War, Savannah today is an industrial center and an important Atlantic seaport. The city is the most populous in the Coastal Georgia region and the fifth-most populous in the state as a whole, with a population of 147,780 at the 2020 census and an estimated 148,808 in 2024. The Savannah metropolitan area, with about 432,000 residents in 2024, is the third-largest metro area in the state.

January 11 is the 11th day of the year in the Gregorian calendar; 354 days remain until the end of the year.