In a small bowl, whisk together the lime juice, olive oil, honey, salt, and pepper until the vinaigrette is fully emulsified.
Place the diced mangoes, minced red onion, and chopped cilantro into a large mixing bowl.
Add the diced avocado to the bowl, taking care to minimize handling to preserve the shape of the cubes.
Drizzle the vinaigrette over the ingredients.
Using a large silicone spatula, gently fold the ingredients together until evenly coated.
Transfer to a chilled serving dish and serve immediately to prevent avocado oxidation.