Quenching and partitioning (or “Q&P”) is a new process that has been under development for the past few years as a means to create strong microstructures containing substantial quantities of retained austenite.  Retained austenite is beneficial to formability and toughness through its transformation induced plasticity (TRIP) response.  The Q&P process is similar to conventional quenching and tempering, except that the initial quenching process is halted at a temperature that results in an incomplete martensitic transformation, and the partitioning step (similar to a tempering step) is intended to move carbon from the supersaturated martensite into the untransformed austenite, thereby stabilizing it at room temperature.  In this presentation, the basic Q&P concepts are introduced to the heat treating community, and selected studies are reviewed which illustrate the physical metallurgical principles and initial applications-oriented research for different types of steels.