In a medium bowl, combine Greek yogurt, olive oil, lemon juice, grated garlic, and season with salt and pepper. Whisk together until smooth.

Rinse cucumbers under cold water, cut in half lengthwise, and slice into ¼-inch thick pieces. Transfer to a large mixing bowl.

Peel and finely chop half a red onion and coarsely chop the dill. Add to the bowl with cucumbers.

Pour the yogurt dressing over the cucumber mixture and gently toss until well coated.

Serve immediately or refrigerate for 15-20 minutes before serving.