Magnetic nanowires form excellent structures for transmitting magnetic domain walls around a network. If the magnetization direction within magnetic domains is taken to represent data values, the nanowires can be used to transport information around an integrated circuit. Furthermore, careful shaping of the nanowires allows Boolean logic functions to be performed on the information, resulting in a nontransistor implementation of digital logic. In this chapter, experimental demonstrations are shown of all of the basic Boolean logic gates, as well as of nanocircuits containing multiple gates. The advantages and limitations of domain‐wall logic are discussed, and the possibilities of ultrahigh‐density three‐dimensional data storage are demonstrated.