As photoresist technology continues to evolve beyond its traditional role in planar semiconductor lithography, it is increasingly positioned as a key enabler of future microsystem innovations. The demands of emerging application domains—such as quantum computing, integrated photonics, flexible electronics, and biointerfacing—are driving a paradigm shift in photoresist functionality, resolution, and integration capacity. This chapter explores how recent breakthroughs in material design, patterning techniques, and multifunctional integration are shaping the trajectory of photoresist development. With attention to scalability, sustainability, and system-level compatibility, the following sections examine how photoresists are being reimagined to meet the diverse and complex requirements of next-generation technologies.