Rinse the lemon balm leaves thoroughly under cold water to remove any dirt or debris. Gently pat them dry with a clean kitchen towel.
In a small saucepan, combine the water and honey. Heat over medium heat until the honey is fully dissolved, stirring occasionally.
Add the lemon balm leaves to the saucepan and reduce the heat to low. Allow the mixture to simmer for 10 minutes, ensuring it doesn’t come to a boil.
Remove the saucepan from the heat and stir in the lemon juice and lemon zest. Let the mixture steep for an additional 5 minutes to infuse the flavors.
Strain the liquid through a fine-mesh sieve into a heatproof pitcher or jar, pressing gently on the leaves to extract all the liquid. Discard the used lemon balm leaves.
Allow the infused liquid to cool to room temperature, then refrigerate until chilled or serve immediately over ice.