Begin by washing all vegetables thoroughly. Chop the cucumbers, sweet bell peppers, red onion, and parsley into bite-sized pieces.
In a small bowl, whisk together the olive oil, lemon juice, salt, and pepper until the mixture is well combined.
In a large mixing bowl, combine the diced cucumbers, sweet bell peppers, red onion, and parsley. Drizzle the dressing over the salad ingredients.
Gently toss all ingredients together until they are evenly coated with the dressing.
Place the salad in the refrigerator for at least 30 minutes before serving to allow the flavors to enhance.
Serve cold as a refreshing side dish or light meal.