Start by mixing your olive oil, lime juice, minced garlic, cilantro, cumin, smoked paprika, chili powder, Mexican oregano, salt, and pepper in a bowl. Whisk until everything is combined.
Place your chicken in a resealable plastic bag or shallow dish. Pour the marinade over it, ensuring each piece is coated on all sides. Seal the bag or cover the dish with plastic wrap and refrigerate for at least 2 hours (longer for deeper flavor).
Fire up your grill to medium-high heat (about 400-450°F). Oil the grates lightly to prevent sticking.
Place the marinated chicken on the grill and close the lid. Cook for 5-7 minutes per side, depending on thickness, until grill marks form and the internal temperature reaches 165°F. Use your tongs to flip the chicken without piercing it to retain its juices.
Once cooked, transfer the chicken to a plate and cover it with foil. Allow it to rest for 5-10 minutes to redistribute the juices and lock in flavor.