Boil water in a large pot and cook the rotini pasta according to package instructions. Drain and cool.
In a large mixing bowl, combine the cooled pasta with cherry tomatoes.
Add diced cucumber and mix well.
Incorporate sliced red onion and bell peppers into the bowl.
Add Kalamata olives and crumbled feta cheese.
In a small bowl, whisk together olive oil and balsamic vinegar.
Pour the dressing over the pasta salad and toss to combine.
Season with salt and pepper to taste.
Cover and refrigerate for at least 30 minutes to allow flavors to meld.
Serve chilled or at room temperature.