In a large mixing bowl, combine the sliced strawberries, blueberries, and raspberries. Gently toss the berries together to mix them evenly.
In a separate pitcher, combine the orange juice and honey. Stir well until the honey is fully dissolved.
Add the mixed berries to the pitcher with the orange juice. Stir gently to combine.
Fill glasses with ice cubes, then pour the berry and juice mixture over the ice, filling each glass about two-thirds full.
Top each glass with sparkling water, stirring gently to combine.
Garnish with fresh mint leaves and serve immediately.