In a small mixing bowl, combine Greek yogurt, olive oil, lemon juice, grated garlic, salt, and pepper. Whisk until smooth, about 2 minutes.

Slice cucumbers in half lengthwise, then into thin half-moons. Finely slice red onion.

In a large bowl, combine sliced cucumbers, red onion, and chopped dill. Toss gently.

Pour dressing over the cucumber and dill mixture. Fold gently to combine.

Serve immediately or chill for 30 minutes before serving.