Cook the penne pasta according to package instructions; drain and cool.
In a large bowl, combine the cooled pasta, cherry tomatoes, cucumber, and red onion.
Add Kalamata olives and crumbled feta cheese to the bowl.
In a separate bowl, whisk together olive oil, red wine vinegar, oregano, salt, and pepper.
Pour the dressing over the pasta mixture and toss to combine.
Taste and adjust seasoning as necessary.
Chill in the refrigerator for at least 30 minutes.
Before serving, give the salad a good toss to redistribute the dressing.
Garnish with fresh herbs if desired.
Serve chilled or at room temperature.