MicroRNAs (miRNAs) are a class of noncoding RNAs that regulate gene expression in cancer cells and cancer stem cells (CSCs) and play an indispensable role in the development of resistance to radiotherapy and chemotherapy in cancer treatment. The dysregulation of miRNAs in CSCs plays a vital role in influencing the features of CSCs and their resistance mechanisms in different forms of cancer. These miRNAs are also engaged in regulating important signaling pathways, such as Notch and Wnt, which have an impact on the behavior of CSCs and their response to treatment. The intricate network of miRNAs and their interactions with essential proteins and major pathways highlights their potential as therapeutic targets for controlling cancer stem cell behavior and improving the outcomes of cancer therapy by understanding their effects. Comprehending the complex relationship between the production of microRNA, the environment surrounding the tumor, and the processes by which cells communicate can provide vital knowledge for developing successful treatments to overcome resistance to chemotherapy and radiation in cancer therapy.