Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper if desired.
In a large mixing bowl, combine the ground turkey, breadcrumbs, egg, minced garlic, parsley, oregano, salt, pepper, and lemon zest. Mix until well combined.
Form the mixture into meatballs about 1 to 1.5 inches in diameter and place them on the lined baking sheet.
Bake the meatballs in the preheated oven for 20 minutes, or until fully cooked and golden brown on the outside.
While the meatballs are baking, prepare the tzatziki sauce. In a separate bowl, whisk together the Greek yogurt, grated cucumber, minced garlic, olive oil, lemon juice, and season with salt and pepper to taste.
Once the meatballs are done, remove them from the oven and let them rest for a few minutes.
Serve the meatballs warm with a generous side of tzatziki.