What is the only bone in the human body not connected to any other bone?

The only bone in the human body not connected to any other bone is the hyoid bone. It is a small, horseshoe-shaped bone in the front of the neck, between the lower jaw and the larynx.

Unlike most bones, the hyoid does not form a joint with another bone. Instead, muscles and ligaments suspend it in place. This unusual arrangement lets it move during swallowing and speech while providing attachment points for the tongue, floor-of-mouth muscles, pharynx, larynx, and epiglottis.

The hyoid is not completely isolated from the skeleton: muscles connect it functionally to the jaw, skull, sternum, and shoulder region. That is why “not connected to any other bone” means it has no direct bony articulation, not that it has no anatomical connections.

A common mix-up is the stapes, the tiny stirrup-shaped bone in the middle ear. The stapes is the smallest bone in the body, but it is joined to neighboring ear bones and therefore is not the answer. Hyoid fractures can also be important in forensic investigations, especially in cases involving neck trauma.