Heat olive oil in a large skillet over medium heat.
Add diced onion and cook until softened, about 3-4 minutes.
Add ground beef and cook until browned, breaking it up with a spoon, about 5-6 minutes.
Add minced garlic and cook for 1 minute until fragrant.
Transfer the cooked beef, onions, and garlic to the slow cooker.
Add diced tomatoes, kidney beans, black beans, tomato sauce, beef broth, chili powder, ground cumin, smoked paprika, dried oregano, salt, and black pepper to the slow cooker.
Stir all ingredients together until well combined.
Cover and cook on low for 5 hours.
After 5 hours, add the egg noodles to the slow cooker, stirring to submerge them in the chili mixture.
Cover and cook on low for an additional 1 hour, or until the noodles are tender.
Stir the chili and noodles before serving to combine everything evenly.