Dimensional metrology tools are increasingly challenged by the continuing decrease in the device dimensions, combined with complex disruptive materials and architectures. These demands are not being met by existing/forthcoming metrology techniques individually. Hybrid metrology (HM), which combines measurements from multiple toolset types to enable or improve the measurement of one or more critical parameters, has recently been incorporated by the industry to resolve these challenges. Before discussing HM, this chapter reviews the salient features of various inline metrology techniques based on the industry’s current challenges and requirements use cases.