Heat a large pot or Dutch oven over medium-high heat. Add the ground beef and cook, breaking it apart with a wooden spoon, until browned — about 6 to 8 minutes. Drain excess fat.
Add the diced onion to the pot and cook for 3 minutes until softened. Stir in the garlic and cook for another minute until fragrant.
Sprinkle in the taco seasoning, cumin, and chili powder, stirring to coat the beef evenly.
Pour in the diced tomatoes, Rotel, black beans, kidney beans, corn, and beef broth. Stir everything together well.
Bring the soup to a boil, then reduce heat to low and let it simmer for 15 minutes, stirring occasionally.
Taste and adjust seasoning with salt and pepper as needed.
Ladle into bowls and pile on your favorite toppings. Enjoy!