Place the lentils, butternut squash, onion, carrots, and garlic in the slow cooker.
Add the diced tomatoes, vegetable broth, cumin, smoked paprika, salt, and black pepper. Stir to combine.
Cover and cook on low for 6 hours.
Stir in the rinsed quinoa. Cover and cook for 1 more hour until the quinoa is tender.
Taste and adjust salt if needed. Sprinkle with fresh parsley before serving.