In a large mixing bowl, whisk the olive oil, lemon juice, oregano, salt, and black pepper until combined.
Add the chickpeas, Kalamata olives, sun-dried tomatoes, cucumber, red onion, and parsley to the bowl.
Toss everything gently until the ingredients are evenly coated with the dressing.
Sprinkle the crumbled feta cheese over the top just before serving.