It has become increasingly appreciated that living mammalian cells are not just complex biochemical reactors but also sophisticated biomechanical systems that can adapt their mechanical properties to various signals and perturbations from the extracellular space, and integrate with intracellular signaling events through a process called mechanotransduction, to regulate cell behaviors. To gain fundamental insights into such biomechanical nature of mammalian cells, many biomechanical tools have been developed with unprecedented spatiotemporal resolutions covering both molecular and cellular length scales. In this chapter, we describe a recently developed biomechanical tool, termed “stretchable micropost array cytometry” (SMAC), which is capable of quantitative control and real-time measurements of both mechanical stimuli and cellular biomechanical responses with a high spatiotemporal subcellular resolution. We further discuss implementations of the SMAC for characterizing cell cytoskeletal contractile force, cell stiffness, and cell adhesion signaling and dynamics at both whole-cell and subcellular scales in real time. We conclude with remarks regarding future improvements and applications of the SMAC for cell mechanics and mechanobiology studies.