Milligan is an unincorporated community in Okaloosa County, Florida, United States. Milligan is located at the junction of U.S. Route 90, (State Road 10) and State Road 4, west-southwest of Crestview.
From June 3, 1915 (when Okaloosa County was formed) until the Yellow River flooded in 1917, Milligan was the county seat.