Boil the Spaghetti: Bring a large pot of salted water to a rolling boil. Add spaghetti and cook according to package instructions until al dente, about 8–10 minutes.

Drain and Cool the Pasta: Drain spaghetti in a colander and rinse under cold water for 1–2 minutes to cool it down.

Prepare the Vegetables: Wash and chop the vegetables. Halve the cherry tomatoes, dice the cucumber and bell peppers, and chop the red onion.

Combine Ingredients in a Bowl: In a large mixing bowl, combine the cooled spaghetti with the chopped vegetables and olives.

Dress the Salad: Pour Italian dressing over the salad and gently toss to coat evenly.

Season to Taste: Sprinkle with salt, black pepper, and Parmesan cheese if desired, and toss again.

Chill Before Serving: Refrigerate for at least 1 hour before serving.