In a large non-stick skillet, brown the ground beef along with the diced onion over medium-high heat. Break up the meat into small pieces until fully browned. Add minced garlic and cook for an additional minute.
Remove the skillet from heat and drain any excess grease if necessary. Transfer the browned meat mixture into the slow cooker. Add crushed tomatoes, diced tomatoes, Worcestershire sauce, chili seasoning, and both cans of rinsed kidney beans.
Mix all ingredients together until well combined, ensuring that the spices are evenly distributed.
Cover with a lid and set the slow cooker to cook on low for about 8-10 hours or on high for approximately 4-5 hours.
Once cooked through, serve the chili hot garnished with toppings such as shredded cheese, sour cream, tortilla chips, or cornbread.