In a bowl, whisk together olive oil, minced garlic, lemon zest, lemon juice, oregano, thyme, salt, and pepper.
Place chicken breasts in a resealable plastic bag and pour the marinade over them. Seal the bag and massage the marinade into the chicken.
Marinate in the refrigerator for at least 30 minutes.
Preheat grill to medium-high heat. Remove chicken from marinade and discard excess marinade.
Grill chicken breasts for about 6-7 minutes on each side or until they are cooked through and no longer pink in the center.
Remove from grill and let rest for a few minutes before serving.