Santa Rosa County is a county located in the U.S. state of Florida. As of the 2015 census, the population was 167,040. Its county seat is Milton.Santa Rosa County is included in the Pensacola-Ferry Pass-Brent, FL Metropolitan Statistical Area.HistorySanta Rosa County was created in 1842. It was named for the Roman Catholic saint, Rosa de Viterbo.Santa Rosa County repealed its prohibition on alcohol in 2007.