Micro/meso-scale mechanical machining (M4) processes are miniaturized versions of conventional machining processes such as milling, drilling, and turning, where material removal is accomplished by physical contact between the micro/meso-scale cutting tool and the workpiece. The objective of this review paper is to provide an assessment of the state-of-the-field related to M4 processes during the last two decades. Key systems-level issues related to the deployment of M4 processes including micro/meso-scale machine tool (mMT) design, sensing/calibration, cutting tools, and lubrication strategies are discussed. Emerging material systems are identified along with the specific challenges posed for the development of microstructure-based process models. The topic of micro/meso-scale machining dynamics is reviewed both in terms of recent research findings as well as unresolved challenges posed by the complexity of experimental characterization and modeling. Finally, key industry trends are discussed along with promising interdisciplinary drivers that are expected to influence this field in the upcoming decade.