Classified as a Concealed Weapon
While some states such as California, Connecticut and Michigan have laws specifically pertaining to collapsible batons, Ohio does not, so expandable batons fall under the general laws relating to concealed weapons. Concealed weapons are generally illegal to carry in Ohio without a proper license, and there is no licensing for collapsible batons or any concealed weapon aside from handguns.
Ohio law allows an argument that a concealed weapon (in this case a baton) is being carried for defensive purposes if the carrier is traveling to or from work and he has a reason to believe he may need to defend himself. This generally means that if the baton is used in a self-defense situation, the carrier can still be arrested at the police officer's discretion but a defense attorney can use self-defense as an acceptable argument to a jury. The same holds true if the baton is kept and used inside the carrier's home or if it was deployed in another self-defense situation where the carrier is engaged in lawful activity. Self-defense is not an acceptable legal defense in circumstances where the defense occurred amidst an illegal act.
Any law enforcement agents from Ohio or other states are exempt from the Ohio concealed weapons statutes and are permitted to carry them in the performance of their job. Likewise, anyone who has a specific license for a collapsible baton that was issued by a state that Ohio has a reciprocity agreement with can legally carry the baton while traveling through the state. The license would no longer apply once the carrier became an Ohio resident and would not apply if the baton was used in a way determined not to be self-defense.