A refrigerator magnet or fridge magnet is a small magnet, often attached to an artistic or whimsical ornament, which may be used to post items such as shopping lists, Christmas cards, child art or reminders on a refrigerator door, or which simply serves as decoration. Refrigerator magnets come in a wide variety of shapes and sizes, and may have promotional messages placed on them. In addition to refrigerators, refrigerator magnets are commonly placed on steel-backed whiteboards and bulletin boards, as well as other metal furniture such as filing cabinets and tool chests. Refrigerator magnets are popular souvenir and collectible objects.

The first refrigerator magnets were inflexible magnets in a cylindrical or rectangular prism shape. Ferrite magnets are commonly used, with decorative elements attached to the magnets with adhesive. They were created in the 1920s.

Later, a flexible magnet was developed, composed of a high-coercivity ferrimagnetic or ferromagnetic compound (usually barium ferrite) mixed with a plastic binder, extruded as a sheet.

Unlike most conventional magnets that have distinct north and south poles, most flexible refrigerator magnets are magnetized during manufacture in a sophisticated magnetization pattern called a Halbach array. This construction almost doubles the magnetic field on the refrigerator side and almost zero magnetic field on the other.

This pattern can be impressed on the sheet by rolling a line of powerful cylindrical permanent magnets arranged with alternating magnetic poles. This pattern can be felt by taking two similar (or identical) refrigerator magnets and sliding them against each other with the refrigerator sides facing each other: the magnets will alternately repel and attract as they are moved a few millimeters. The pole-pole distance is on the order of 5 mm, but varies with manufacturer.

Refrigerator magnets may be designed to decorate refrigerators. Refrigerator magnets are also widely given away as promotional products. Refrigerator magnets can be made from rubber, PVC, polyresin, metal, porcelain, epoxy, or a mixture of some of these materials. A business can put their logo on the magnets for marketing purposes. In addition to their promotional value, refrigerator magnets are popular because they combine functionality with decoration, allowing people to display notes, photos, or shopping lists while adding color and personality to the kitchen.

Refrigerator magnets can also be souvenirs. Many souvenir shops throughout the world sell magnets with local charms printed.

Collecting magnets is a hobby, with some collectors specializing in magnets from their travels, or of a particular theme. They are sold at souvenir shops worldwide. There is no generally recognized term (e.g. numismatics for currency collecting) for magnet collecting. A Russian collector has proposed the term memomagnetics (Russian: мемомагнетика), derived from the words memoriale (Latin) and magnetis (Greek) A collector of magnets would be called memomagnetist. These terms have been used by at least one Russian online community for magnet collectors.