Heat the olive oil in a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Stir in the diced onion and minced garlic. Cook for 3 minutes until the onion softens.
Add the sliced zucchini and chopped tomatoes. Stir to combine and let the vegetables cook for 2 minutes.
Pour in the beef broth. Add the Italian seasoning, salt, and black pepper. Bring the mixture to a simmer.
Reduce the heat to low, cover the pot, and cook for 15 minutes until the zucchini is tender but not mushy.
Taste and adjust salt if needed. Ladle into bowls and sprinkle with the chopped fresh parsley before serving.