- The Florida Department of Health in Duval County, formerly referred to as the Duval County Public Health Unit and later the Duval County Health Department, was established in October 1938. It was the 16th unit in the state to become part of the state-county system.
- Its formation was due to the efforts of a concerned Health Advisory Board member, Mrs. Willis M. Ball (Jessie A.) Dupont, Member of the Health Advisory Board. The new organization was to be the companion of the Duval County Health Department, founded in 1938. The Jacksonville City Health Department was founded on July 14, 1889.
- The population of Duval County and Jacksonville in 1938 was approximately 176,000 people.
- Kolbein K. Waering, M.D., was selected as the first Health Officer and he was joined by seven public health nurses, two sanitarians and one clerk at the headquarters on First and Market Streets.
- Funding for the unit was shared by the Florida State Board of Health, the Board of County Commissioners, the United States Public Health Service, the Children's Bureau of Labor Department and the Works Progress Administration.
- After interim moves to 1050 Hendricks Avenue in 1945, the County Courthouse and to 962 Main Street, the new unit began operation at 515 West Sixth Street in 1972.
- Consolidation of City/County Government occurred July 1968, creating a combined department with the county health officer serving concurrently as the Chief of the Health Division within the Health, Welfare and Bio-Environmental Services Department, City of Jacksonville.
- Reorganization of the City/County health departments occurred December 1987 resulting in the creation of a new combined position to serve as both the HRS Duval County Public Health Unit Director and as the Director of the Health, Welfare and Bio-Environmental Services, City of Jacksonville.