Heat a large pot over medium heat. Add ground beef or turkey and cook until browned, breaking it up as it cooks.
Add chopped onion and cook for 3–4 minutes until softened. Stir in garlic and cook for 30 seconds until fragrant.
Drain excess fat if needed, then sprinkle taco seasoning over the meat and stir to coat evenly.
Add diced tomatoes, black beans, kidney beans, corn, and broth. Stir well to combine.
Bring the soup to a gentle boil, then reduce heat to low.
Simmer uncovered for 20–25 minutes, stirring occasionally, until flavors are well blended.
Taste and adjust seasoning with salt and black pepper before serving.
