In a bowl, whisk together the olive oil, lemon juice and zest, orange juice and zest, minced garlic, dried oregano, dried thyme, salt, and pepper.
Place the chicken cubes in a bowl.
Pour citrus marinade over the chicken.
Toss to coat evenly.
Let the meat marinate in the refrigerator for at least 30 minutes, or up to 4 hours for maximum flavor.
Preheat your grill to medium-high heat.
Thread the marinated chicken and vegetables onto the skewers, alternating between chicken, zucchini, bell peppers and onions.
Place the skewers on the preheated grill and cook for about 8-10 minutes, turning occasionally, until the chicken is cooked through and the vegetables are softened.
Remove the skewers from the grill and cover with aluminum foil.
Serve the grilled chicken skewers hot.
Enjoy!