Holt is an unincorporated community located in Okaloosa County, Florida, United States. Its area calling code is 850 and its ZIP code is 32564.Holt is located in western Okaloosa County along US 90 and County Road 189. South along CR 189 is an interchange for Interstate 10. Blackwater River is approximately two miles to the east of the town to enjoy clean freshwater swimming and fishing.