Prepare and measure out the ingredients: cut the watermelon into 1-inch cubes, pit and slice the peaches into thin wedges, chop the mint leaves roughly, and set all aside in a large mixing bowl.
Sprinkle the salt over the prepared fruit mixture in the bowl, then add the chopped mint. Gently toss the ingredients together to evenly distribute the seasoning and mint flavor.
Juice the lime using a lime juicer until you have about 2 tablespoons of fresh lime juice. Pour the lime juice over the fruit mixture.
Gently fold the ingredients together with a large spoon until everything is uniformly coated and well combined. Watch for the fruit to release their juices, creating a light, flavorful syrup.
Let the salad sit for 5 minutes to allow the flavors to meld, then give it a final gentle stir before serving.
Serve the fruit salad in individual bowls, garnished with additional mint leaves if desired, and enjoy its fresh, juicy textures.