Prepare the Marinade: In a bowl, whisk together balsamic vinegar, honey, Dijon mustard, minced garlic, oregano, salt, and pepper.
Marinate the Chicken: Place chicken breasts in a resealable bag or dish and pour the marinade over them. Seal and refrigerate for at least 15 minutes, or up to 2 hours for more flavor.
Preheat the Air Fryer: Preheat your air fryer to 375°F (190°C).
Cook the Chicken: Remove the chicken from the marinade and shake off excess. Spray the air fryer basket with olive oil spray and place the chicken breasts in a single layer. Cook for 15-18 minutes, flipping halfway through, until the internal temperature reaches 165°F (74°C).
Glaze and Serve: Brush the chicken with any leftover marinade during the last few minutes of cooking. Remove from the air fryer and let rest for a few minutes before slicing. Serve with your favorite sides.