Deubiquitinases or DUBs have emerged as pivotal regulators in cellular homeostasis, coordinating the delicate balance of protein ubiquitination and deubiquitination. Their versatile roles span from controlling protein turnover to modulating signal transduction pathways, thereby influencing diverse cellular processes such as DNA damage repair, apoptosis, and immune responses. This review comprehensively explores the current understanding of DUBs, elucidating their structural diversity, catalytic mechanisms, physiological functions, and implications in human diseases. Moreover, we discuss the therapeutic potential of targeting DUBs in various pathological conditions, highlighting recent advancements and challenges in developing DUB-specific inhibitors.