Advancements in Optical Methods, Digital Image Correlation & Micro-and Nanomechanics, Volume 4 of the Proceedings of the 2022 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the fourth volume of six from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of optical methods ranging from traditional photoelasticity and interferometry to more recent DIC and DVC techniques, and includes papers in the following general technical research areas: DIC Methods & Its Applications Photoelsticity and Interferometry Applications Micro-Optics and Microscopic Systems Multiscale and New Developments in Optical Methods Extreme Nanomechanics In-Situ Nanomechanics Expanding Boundaries in Metrology Micro and Nanoscale Deformation MEMS for Actuation, Sensing and Characterization 1D & 2D Materials.