1In a large bowl, combine the sliced cucumbers, diced tomatoes, and thinly sliced onions.
In a small bowl, mix the mayonnaise and lemon juice until well combined.
Pour the mayonnaise mixture over the vegetables and toss gently to coat.
Season with salt and pepper to taste.
Chill the salad in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.
Serve cold and enjoy your refreshing Cucumber Tomato Onion Salad.