ONFIRE is a database of monthly burned area data from Observed National inventories of FIREs tailored for researchers interested in intercomparison and assessment exercises. In these regions there are inventories of fire histories already used in several studies: Australia (1950-2020), Europe (1980-2020), Canada (1984-2019), Chile (1984-2020) and U.S. (1992-2018). These archives, although publicly available, can be difficult to use since obtaining, storing and pre-processing them is a time-consuming task also because are in multiple record formats. Here, we provide this integrated dataset based on official fire statistics of ground observation. The ONFIRE data is provided over its length of record for each region and up to 2020 (if available) on a common 1º × 1º grid.