Prepare the chicken thighs by patting them dry with paper towels.
Season both sides of the chicken thighs with salt, pepper, garlic powder, onion powder, and paprika.
Place the seasoned chicken thighs in the slow cooker.
Pour the barbecue sauce over the chicken, ensuring all pieces are coated.
Cover the slow cooker with the lid.
Cook on low for 6-8 hours or on high for 3-4 hours.
Check the chicken for doneness; it should reach an internal temperature of 165°F (75°C).
Once cooked, remove the chicken thighs and let them rest for a few minutes.
Stir the sauce in the slow cooker before serving.
Serve the chicken thighs with the sauce on top, garnished with fresh parsley.