In a slow cooker, place the chicken breasts in a single layer.
In a medium bowl, whisk together the ranch dressing mix, brown gravy mix, chicken broth, cream of chicken soup, garlic powder, black pepper, onion powder, and olive oil until well combined.
Pour the mixture over the chicken in the slow cooker, ensuring the chicken is well coated.
Cover and cook on low for 6-7 hours or on high for 3-4 hours, until the chicken is cooked through and tender.
Once cooked, shred the chicken using two forks and stir it back into the gravy. Adjust salt to taste.
Serve over rice, mashed potatoes, or with bread for dipping.