Chitosan-based micelles have gained significant attention in the fields of drug delivery and bioimaging due to their versatile properties, including biocompatibility, biodegradability, and the ability to encapsulate a wide range of therapeutic agents. This chapter provides a comprehensive overview of the design, synthesis, and application of chitosan-based micelles, focusing on their dual role as carriers for drug delivery and agents for bioimaging. The chapter begins with a discussion of chitosan’s unique chemical structure and its role in the formation of micelles through self-assembly. Key factors affecting micelle stability, drug encapsulation efficiency, and release kinetics are explored in detail. Various preparation techniques and functionalization strategies for chitosan-based micelles are outlined, emphasizing their adaptability for different drug delivery platforms, including oral, intravenous, and targeted therapies. In addition to drug delivery, the chapter delves into the applications of chitosan-based micelles in bioimaging, including fluorescence and magnetic resonance imaging (MRI). The potential of these micelles in theranostics—combining drug delivery with real-time imaging capabilities—is also examined, providing insight into their role in personalized medicine. The chapter concludes by addressing recent advancements in stimuli-responsive micelles and hybrid systems, along with challenges related to scalability and clinical translation. This comprehensive overview positions chitosan-based micelles as a promising tool in the development of next-generation drug delivery and imaging technologies.