Spray the inside of your crockpot or slow cooker generously with non-stick cooking spray, or line with a slow cooker liner for easy cleanup.
Season chicken breasts on both sides with salt, pepper, onion powder, and garlic powder. Place flat in the bottom of the crockpot.
In a bowl, whisk together the BBQ sauce, Italian dressing, brown sugar, and Worcestershire sauce until fully combined.
Pour the sauce mixture evenly over the chicken breasts in the crockpot. Place the lid on.
Cook on HIGH for 2.5 to 3 hours, or on LOW for 5 to 6 hours. Check at the shortest time first.
Use an instant-read meat thermometer to confirm the chicken has reached an internal temperature of 165°F before serving.
Once fully cooked, use two large forks to shred the chicken directly in the crockpot. Stir to coat all the shredded chicken in the sauce.
Serve on buns for BBQ pulled chicken sandwiches, or use in tacos, pizza, nachos, rice bowls, over baked potatoes, or on its own. Enjoy!