In a mixing bowl, whisk together the Greek yogurt, olive oil, lemon zest, lemon juice, pressed or minced garlic, dried Italian seasoning, kosher salt, and black pepper until smooth.
Add the chicken thighs to the marinade and toss to coat each piece thoroughly.
Let the chicken marinate for at least 15 minutes at room temperature, or cover and refrigerate for up to overnight for more flavor.
When ready to bake, preheat the oven to 425°F (220°C) and line a baking sheet with aluminum foil.
Arrange the marinated chicken thighs in a single layer on the prepared baking sheet, leaving a little space between pieces.
Bake for 20–25 minutes, or until the chicken is cooked through and registers 165°F (74°C) at the thickest part.
Remove from the oven and let rest a few minutes before serving.