In a large mixing bowl, combine the cubed cantaloupe, honeydew melon, and diced cucumber.
Add the crumbled feta cheese and chopped mint leaves to the bowl.
In a small bowl, whisk together the olive oil, lime juice, salt, and pepper until well combined.
Drizzle the dressing over the melon mixture and gently toss to combine, ensuring everything is evenly coated.
Chill the salad in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.
Serve chilled as a refreshing side dish or light meal.