In a small bowl, whisk together olive oil, red wine vinegar, garlic, lemon zest, lemon juice, oregano, salt, and black pepper until well combined.
Bring 4 quarts of water and 1 tablespoon of salt to a rolling boil in a large pot.
Add the rotini pasta and cook according to package directions, usually 7–10 minutes, until al dente.
Drain the pasta and rinse under cold water to stop the cooking process.
In a large mixing bowl, combine the cooled pasta, cucumber, bell pepper, red onion, grape tomatoes, feta cheese, and olives.
Pour the dressing over the salad.
Toss gently until everything is evenly coated.
Taste and season with additional salt and pepper as needed.
Serve immediately or chill for 30 minutes before serving for even better flavor. This Easy Greek Pasta Salad tastes even better after the ingredients have had time to marinate together.