In a small bowl, whisk together chicken broth, lemon juice, lemon zest, garlic, salt, pepper, and Italian seasoning.
Place the chicken breasts in the slow cooker and pour the lemon-garlic mixture over the top.
Drizzle olive oil over the chicken, cover, and cook on low for 6 hours or on high for 3 hours.
Once done, garnish with chopped fresh parsley and serve warm with your favorite sides.