Heat oven to 400°F. Brown ground beef in large nonstick skillet over medium heat 6 minutes. Add onion and bell pepper; cook until beef is not pink and vegetables are crisp-tender. Pour off drippings. Season with salt and pepper.
Place pizza crust on baking sheet. Top with beef mixture, then cheese. Bake in 400°F oven 8 to 10 minutes or until edge of crust is golden brown and cheese is melted.