A chamber safety device is configured to be inserted into one or more openings of a weapon, such as the loading/ejection port(s) or barrel of a shotgun, rifle or handgun. When the chamber safety device is inserted into the one or more opening(s), the weapon is not capable of firing and/or being loaded with ammunition due to the fact that no bullet or shell can be inserted into the firing chamber and/or the weapon firing mechanism cannot come in contact with a bullet or shell located in the firing chamber.