Liquidmetal and Vitreloy are commercial names of a series of amorphous metal alloys developed by a California Institute of Technology (Caltech) research team and marketed by Liquidmetal Technologies. Liquidmetal alloys combine a number of desirable material features, including high tensile strength, excellent corrosion resistance, very high coefficient of restitution and excellent anti-wearing characteristics, while also being able to be heat-formed in processes similar to thermoplastics. Despite the name, they are not liquid at room temperature.

Liquidmetal was introduced for commercial applications in 2003.^{[citation needed]} It is used for, among other things, golf clubs, watches and covers of cell phones.

The alloy was the end result of a research program into amorphous metals carried out at Caltech. It was the first of a series of experimental alloys that could achieve an amorphous structure at relatively slow cooling rates.^{[citation needed]} Amorphous metals had been made before, but only in small batches because cooling rates needed to be in the millions of degrees per second. For example, amorphous wires could be fabricated by splat cooling a stream of molten metal on a spinning disk. Because Vitreloy allowed such slow cooling rates, production of larger batch sizes was possible. More recently, a number of additional alloys have been added to the Liquidmetal portfolio. These alloys also retain their amorphous structure after repeated re-heating, allowing them to be used in a wide variety of traditional machining processes.