Place the ground turkey in the bottom of the slow cooker and break it into small pieces with a spoon.
Add the cubed sweet potatoes, diced onion, and minced garlic on top of the turkey.
Sprinkle the dried thyme, salt, and black pepper over the ingredients.
Pour the chicken broth into the slow cooker.
Stir everything together gently to distribute the seasonings.
Cover and cook on low for 6 to 7 hours until the sweet potatoes are soft and the turkey is fully cooked.
Stir the soup once more before serving to blend the broth.