Quantum dots (QDs) are with exceptional physicochemical and biological properties, making them highly versatile for a wide range of applications in cancer therapy. One of the key features of QDs is their unique electronic structure, which gives them functional attributes. Notably, their photoluminescence can be strong and adjustable, allowing them to be effectively used in fluorescence based diagnosis such as biosensing and bioimaging. In addition, QDs demonstrate an impressive capacity for loading cargo, making them ideal for drug delivery applications. Moreover, their ability to absorb incident radiation positions QDs as promising candidates for cancer-killing techniques like photodynamic therapy. The objective of this comprehensive review is to present a current and comprehensive overview of the recent advancements in utilizing QDs as multifunctional and innovative biomaterials. This review focuses on elucidating the biological, electronic, and physicochemical properties of QDs, along with discussing the technical advancements in QD synthesis. Furthermore, it thoroughly explores the progress made in utilizing QDs for diagnosis based on biosensing, bioimaging, and therapy applications including drug delivery and necrosis, highlighting their significant potential in the field of cancer treatment. Furthermore, the review addresses the current limitations associated with QDs in cancer therapy and provides valuable insights into future directions, thereby facilitating further advancements in this field. By presenting a comprehensive and well-structured overview, this review serves as an authoritative and informative resource that can guide future research endeavors and foster continued progress in the field of QDs for cancer therapy.