Place the chicken breasts in an even layer at the bottom of a 4–6 quart slow cooker.
Add the halved potatoes on top of the chicken, spreading them out evenly.
In a small bowl, combine melted butter, minced garlic, Italian seasoning, salt, and black pepper.
Pour the garlic butter mixture evenly over the chicken and potatoes.
Cover and cook on low for 2–4 hours, depending on your slow cooker and the thickness of the chicken.
Add the green beans during the last 30–60 minutes of cooking time.
Once the chicken is tender and the potatoes are soft, spoon some of the garlic butter sauce over everything before serving.
This Slow Cooker Garlic Butter Chicken & Potatoes dish is best served warm straight from the slow cooker.