DeBary is located on the north bank of the St. Johns River near Lake Monroe. Oliver and Amanda Arnett bought a large chunk of land in the area in 1866 and built a home on it. Then they sold some 400 acres to a Britich wine merchant named Earl (Samuel) Frederick deBary in 1871. DeBary built an 8,000-square-foot mansion on the property and entertained visitors like Presdents Ulysses S. Grant and Grover Cleveland. Over time he built his estate up to about 9,000 acres and planted oranges groves and pecan trees. DeBary went on to build a steamship service on the St. Johns River to deliver his agricultural goods to market. He acquired several steamships, then merged his line to create the DeBary-Baya Merchants Line with 13 steamboats and a crew of 3,000. Then he sold the company to the Clyde Line in 1889.

Frederick DeBary died in 1898. His mansion is now fully restored and listed on the National Register of Historic Places. His estate has been reduced to 10 acres in the heart of what is now incorporated as the City of DeBary.

The population of DeBary is up more than 24% since 2000.