Bring a large pot of salted water to a boil.
Add spaghetti and cook according to package instructions until al dente.
Drain the spaghetti and rinse under cold water to cool.
In a large bowl, combine cherry tomatoes, bell pepper, black olives, cucumber, and red onion.
Add the cooled spaghetti to the vegetable mixture.
In a small bowl, whisk together olive oil, lemon juice, salt, and pepper.
Pour the dressing over the spaghetti and vegetables.
Toss gently to combine all ingredients thoroughly.
Adjust seasoning if needed.
Garnish with fresh parsley before serving.