Samarium (Sm) is a metallic chemical element with atomic number 62. It is a so called rare earth metal. There are several naturally occurring samarium isotopes, but ¹⁵²Sm (62 protons, 90 neutrons) is the most abundant.

Industrial applications include the very strong samarium-cobalt magnets. While they are not quite as strong as neodymium magnets, they are more heat resistant.

The radioactive samarium-153 isotope is sometimes used in cancer treatment, and the stable samarium-149 isotope is sometimes used in nuclear reactor control rods.