Alnico magnets are magnets composed of iron, cobalt, nickel, aluminium, and copper. They can be magnetized to produce strong magnetic fields. Of the more commonly available magnets, only rare-earth magnets such as samarium-cobalt and neodymium-iron are stronger. Alnico magnets produce magnetic field strength at their poles as high as 1500 gauss, or about 3000 times the strength of the earth's magnetic field.

Alnico has one of the highest Curie points of any magnetic material, around 800 degrees celsius.

Alnico magnets are used in electric electric motors, sensors, and loudspeakers. Alnico is produced by casting or sintering processes.

Some types of Alnico are isotropic, meaning they can be efficiently magnetized in any direction. Other types, such as Alnico 5 and Alnico 8 are anisotropic, meaning they have a preferred direction of magnetization, or orientation. Anisotropic types generally have greater magnetic capacity in their preferred orientation than isotropic types. Anisotropic Alnico magnets are oriented by heating them above a critical temperature, and cooling them in the presence of a magnetic field.