In a 6 to 8 quart stockpot, add ground beef and chopped onion.
Brown over medium high heat and then drain off any excess liquid.
Add ranch dressing mix, taco seasoning mix, kidney beans, whole kernel corn and diced tomatoes.
Stir together well.
Bring to a boil.
Reduce the heat, cover and let simmer for 15 - 30 minutes.