In situ hydrogels have emerged as a promising platform for controlled drug delivery. These hydrogels can be formulated to undergo phase transition in response to specific stimuli, allowing for targeted and prolonged release of therapeutic agents. Recent advancements in hydrogel technology have led to the development of various in situ gelling systems, including thermoresponsive, UV-responsive, and ion-mediated cross-linking systems. These systems have shown great potential in cancer therapy, with several commercial products utilizing hydrogels to improve drug effectiveness while reducing adverse effects. Additionally, in situ hydrogels have been explored for localized drug delivery in delicate areas. This chapter provides an overview of the current status and future directions of in situ hydrogels in drug delivery. We discuss the development of various in situ gelling systems, their applications in cancer therapy, and their potential for targeted and personalized treatment. Furthermore, we highlight the use of UV-responsive in situ gels for controlled drug delivery. Overall, in situ hydrogels hold great promise for revolutionizing treatment paradigms in various medical fields, and continued research in this area is expected to lead to more sophisticated and effective systems for drug delivery.