This article reviews a recently proposed new class of spin transistors referred to as spin metal-oxide-semiconductor field-effect transistors (spin MOSFETs), and their integrated circuit applications. The fundamental device structures, operating principle, and theoretically predicted device performance are presented. Spin MOSFETs potentially exhibit significant magnetotransport effects, such as large magneto-current, and also satisfy important requirements for integrated circuit applications such as high transconductance, low power-delay product, and low off-current. Since spin MOSFETs can perform signal processing and logic operations and can store digital data using both charge transport and spin degrees of freedom, they are expected to be building blocks for memory cells and logic gates in spin-electronic integrated circuits. Novel spin-electronic integrated circuit architectures for nonvolatile memory and reconfigurable logic employing spin MOSFETs are also presented.