Prepare the dressing by mixing Greek yogurt, olive oil, lemon juice, grated garlic, salt, and black pepper in a small bowl until smooth.

Slice the red onion thinly and cut cucumbers in half lengthwise, then slice each half into approximately 3mm thick pieces.

In a large salad bowl, combine the sliced cucumbers, red onion, and chopped dill. Pour the dressing over and toss gently until well coated.

Serve immediately at room temperature or refrigerate until ready to serve.