The legislature of the Republic of Texas authorized Leon County in 1846 from part of Robertson County, and named it in honor of Martín De León, the founder of Victoria, Texas. However, local tradition holds that it is named for a yellow wolf of the region commonly called the león (“lion” in Spanish). The county was organized that same year with its first county seat at Leona. In 1851 the county seat was moved to Centerville since Leona was in the far southern part of the county.
The 1886 Leon County Courthouse was designed by architect George Edwin Dickey of Houston, incorporating remnants of an earlier 1858 courthouse that was destroyed by fire. The courthouse was rededicated on July 1, 2007 following a full restoration to a 1909 date.