Marinate the Chicken: In a mixing bowl, whisk together olive oil, lemon juice, lemon zest, garlic, thyme, rosemary, salt, and pepper. Add chicken thighs and coat them well. Cover and refrigerate for at least 30 minutes.
Preheat the Grill: Heat your grill to medium-high heat and lightly oil the grates.
Grill the Chicken: Remove chicken from the marinade, allowing excess to drip off. Grill for about 6 minutes on each side until fully cooked (internal temperature should reach 165°F).
Serve: Allow the chicken to rest for a few minutes before slicing. Enjoy it warm with your favorite sides.