Spintronics is an emerging technology in which the spin of the electron is used to form a new generation of radiation-hard, nonvolatile, low-energy devices. To date, most interest has focused on memory applications such as hard drive read heads or on future replacements for dynamic random-access memory and battery-backed static random-access memory. In this chapter, we discuss the possibility of using spintronics as a route to three-dimensional integrated circuits. Spintronics is an interesting candidate for three-dimensional architectures because high levels of functionality can be achieved from simple, thin magnetic films without the need for any top contacts or gate electrodes. Furthermore, thin magnetic layers can be easily coupled to each other simply by inserting a carefully selected nonmagnetic material between them. Finally, spintronic devices can usually be designed to minimize thermal dissipation from the magnetic element itself, meaning that power dissipation from the center of a three-dimensional ensemble of elements would not be excessive. These features open up the possibility of stacking highly functional but structurally simple units on top of each other, allowing data to be held, moved, and processed in a vertical direction as well as in the conventional lateral directions.