Observed increases in wildfire activity across the contiguous United States, which have occurred amid a warming climate and expanding residential footprint within flammable landscapes, illustrate the urgency of understanding near-future changes in fire regimes. Here, we use a statistical model including future projections of both human population distribution and atmospheric conditions from climate models to predict the number, size, and cumulative area burned by wildfires. We find an overall increase in both the number of fires (+56%) and total burned area (+60%) during 2020-2060 relative to a 1984-2019 baseline, as well as ubiquitous increases in area burned (+63%) by the largest fires. Additionally, we predict the emergence of observationally unprecedented fire frequency in eastern U.S. locations where wildfire was rare historically (+71%), and unprecedented increases in the size of the largest fires in the Western U.S. where fires were historically common—underscoring the need to prepare for more frequent and severe fire even in communities unaccustomed to them.