Anticancer drug resistance remains a major impediment to the successful treatment of cancer. Over the years, specific cell types, multiple genes, and biochemical pathways have been reported to contribute to the process of resistance. Recently, non-coding RNAs such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) were implicated as important mediators of drug-resistant phenotypes in many different cancers. Non-coding RNAs constitute powerful biomolecules, and numerous miRNAs and lncRNAs have been identified that modulate the sensitivity of cancer cells for specific anticancer drugs. In-depth studies of these RNAs and the genes and biochemical pathways they regulate reveal novel and important mechanisms of resistance that may be inhibited to prevent or overcome resistance. Moreover, specific miRNAs or lncRNAs may be instrumental as biomarker signaling drug resistance or can be exploited as a therapeutic target or anticancer agent. This special issue aims to highlight the unique functional involvement of non-coding RNAs in anticancer drug resistance and their use as a biomarker and therapeutic target in this setting. The main challenge for the near future is how to use these novel insights to reverse anticancer drug resistance and improve chemotherapy for the cancer patient.