Heat oven to 400°F. Brown ground beef in large nonstick skillet over medium heat 6 minutes. Add onion and bell pepper; continue cooking until beef is not pink and vegetables are crisp-tender, breaking beef up into small crumbles. Pour off drippings; season with salt and pepper.
Place pizza crust on ungreased large baking sheet. Spoon beef mixture evenly on pizza crust; sprinkle with cheese. Bake in 400°F oven 8 to 10 minutes or until cheese is melted. Cut into 8 wedges.