In a medium bowl, add orange juice, lime juice, olive oil, Tajin, salt, and pepper and whisk vigorously to combine. Set aside.
Add the chicken to a large shallow baking dish (a gallon size zip-top bag will work too) and pour the marinade over the chicken, making sure all the meat is well coated. Cover with plastic wrap and refrigerate for at least 1 hour or up to 6 hours.
Preheat grill to medium-high heat. Remove chicken from the marinade and place on the grill. Cook for 5-10 minutes on each side until the internal temperature reaches 165 degrees. Remove chicken from the grill and allow to rest 5 minutes before serving. Garnish with cilantro and lime wedges, if desired.
Recipe by Love Grows Wild at https://lovegrowswild.com/2023/06/grilled-tajin-chicken/