It is well known that saccharides and their glycoconjugates can have an important influence on various serious pathologic stages such as cancer. They can regulate tumor proliferation, invasion, hematogenous metastasis, and angiogenesis. These facts clearly show the importance of cancer saccharide recognition. In medicine, sensor analysis is one of the best methods for recognition and determination of biologically important analytes. The development and study of sensors for saccharide tumor markers can open a new way for their detection. Therefore, this review is focused on recognition of saccharide-based cancer markers by natural or synthetic selective ligands working as bio- and chemosensors. The design and application of these ligands for cancer diagnosis is a useful direction of research. Moreover, it also opens the possibility of using these agents for the targeted drug transport required for advanced anticancer therapy.