Ferritin is a ubiquitous iron storage protein responsible for maintaining the iron homeostasis in living organism and thereby protects the cell from oxidative damage. The ferritin protein cages have been used as a reaction vessel for the synthesis of various non-native metallic nanoparticles inside its core and also used as a nanocarrier for various applications. Lack of suitable non-viral carrier for targeted delivery of anticancer drugs and imaging agents is the major problem in cancer therapy and diagnosis. The pH dependent reversible assembling and disassembling property of ferritin renders it as a suitable candidate for encapsulating a variety of anticancer drugs and imaging probes. Ferritins external surface is chemically and genetically modifiable which can serve as attachment site for tumor specific targeting peptides or moieties. Recent studies, further establishes ferritin as a multifunctional nanocarrier for targeted cancer diagnosis and therapy. Moreover, the biological origin of these protein cages makes it a biocompatible nanocarrier that stabilizes and protects the enclosed particles from the external environment without provoking any toxic or immunogenic responses. This review mainly focuses on the application of ferritin nanocages as a novel non-viral nanocarrier for cancer therapy and it also highlights various biomedical applications of ferritin nanocages.