Organoid technology has become a viable tool for advancing biomedical research and its application in clinical settings, particularly in cancer, seeking to improve the therapeutic potential of tumors and offering a more thorough understanding of the tumor microenvironment (TME), metabolism, challenges, and drug resistance. In the current book chapter, we will address how 3D co-culture methods can create matrices that have strong biophysical and biochemical properties and resemble the natural extracellular matrix (ECM). Furthermore, the book chapter will provide an overview of organoids as a novel model system in cancer research, discussing their various types and different applications. Engineering microenvironments for organoid culture and the nature of organoid microenvironments, as well as decellularized ECM and other naturally derived proteins for organoid culture, are also comprehensively addressed. We will also look at the shortcomings of current research models and present the most recent developments in biomaterials science and engineering methods to create more pertinent organoids. By the end of this chapter, we will present the applications of organoids in the generation of immune cells as well as to advance anti-tumor adoptive T cell therapy and dendritic cell-based vaccination. Finally, we present the future avenues for advancing organoid applications in cancer research with the main goal to accelerate the development of new diagnostic markers and different types of anti-tumor personalized therapies.