The main sweetener in traditional Southern sweet tea is sugar.
Southern sweet tea is typically made by adding granulated sugar or simple syrup to black tea while the tea is still hot. Heat helps the sugar dissolve evenly before the drink is chilled and poured over ice. Lemon is a common garnish or flavoring, but it is not the primary sweetener.
Sweet tea began as a relatively expensive drink because tea, sugar, and especially ice were once costly or difficult to obtain. The oldest known sweet-tea recipe was published in 1878 in Housekeeping in Old Virginia, and it used green tea. Black tea later became dominant, particularly after World War II disrupted American access to major green-tea sources in Asia.
Honey, maple syrup, and corn syrup may appear in modern adaptations, but they are not the traditional answer. Sugar levels can vary dramatically by recipe; some commercial or restaurant versions are exceptionally sweet, which is why sweet tea is often treated as a defining Southern beverage rather than merely iced tea with flavoring.