St. Johns County is one of the two original counties created when control of the Florida territory was ceded to the United States in 1821. The county was named for the St. Johns River and the county seat is St. Augustine. The original county encompassed all of peninsular Florida with Escambia County governing what is now the panhandle.
The office of the Circuit Court Clerk has land records from 1821 along with marriage, divorce and probate records beginning in later periods. See also the Spanish Land Grants page for property records prior to Florida becoming a United States territory.
View an interactive map showing how the county boundaries changed over time courtesy Maps of America – Florida Boundaries.