Cadmium (Cd) is a metallic chemical element with atomic number 48. The main industrial use of cadmium is in batteries, for example in rechargeable nickel-cadmium batteries, but cadmium is also used in nuclear reactor control rods where it absorbs neutrons to help keep the chain reaction under control.

There are eight naturally occurring cadmium isotopes, and ¹¹⁴Cd is the most abundant of them.