There is no definitive answer to this question as it depends on a number of factors, including the individual's age, health, and lifestyle. However, some experts believe that the hardest bone in the human body is the jawbone. The jawbone is made up of a number of different bones, including the temporal bone and the mandible (lower jawbone). These bones are all connected by tough ligaments and muscles, which give them a great deal of strength. The jawbone also has a very dense outer layer of compact bone, which makes it resistant to fractures.