Add the onion, carrots, celery, garlic, diced tomatoes, white beans, vegetable broth, Italian seasoning, salt, and black pepper to the slow cooker.
Stir everything together, then cover and cook on low for 6 hours.
Stir in the pasta, cover again, and cook on high for 20 to 25 minutes until the pasta is tender.
Taste and adjust salt or pepper if needed before serving.
Notes
Add the pasta only at the end so it stays firm instead of turning mushy. Leftovers thicken as the pasta absorbs broth, so stir in a splash of water or broth when reheating. If you want to prep ahead, cook the soup without pasta and add freshly cooked pasta when serving.Course: Soup
Cuisine: Italian
Equipment: Slow Cooker