Heat olive oil in a large pot or Dutch oven over medium heat. Add ground turkey and cook until browned, breaking it up with a spoon. Drain any excess fat.
Add chopped onion and minced garlic to the pot. Cook until the onion is softened, about 5 minutes.
Stir in diced tomatoes, black beans, kidney beans, corn, taco seasoning, and ranch seasoning.
Pour in chicken broth and bring the soup to a simmer.
Reduce heat to low, cover, and let it simmer for at least 15-20 minutes to allow the flavors to meld.
Serve hot with your favorite toppings.
Notes
For a spicier soup, add a pinch of cayenne pepper or a chopped jalapeño with the onion.
This soup freezes well. Store in airtight containers for up to 3 months.