Make the salad dressing by combining the olive oil, lemon juice and zest, dried oregano, minced garlic clove, salt, and pepper in a bowl. Mix it with a fork or whisk until well-combined.
Cut the cherry tomatoes in half and thinly slice the red onion. Add the tomatoes, onions, and pitted olives to a large mixing bowl.
Pour the salad dressing over the tomatoes, onions, and olives, and mix to combine everything.
Add the finely chopped mint on top and mix everything well.
Transfer the salad to a serving bowl and top with crumbled feta cheese.