Supramolecular polymers (SPs) have attracted broad interest because of their intriguing features and functions. Host-guest interactions often impart tunable physicochemical properties, reversible hierarchical organization, and stimuli-responsiveness to SPs for diverse biomedical applications. Characterized by strong but dynamic interactions with guest molecules, cucurbit[n]uril (CB[n]) has shown great potential as an important building block of various functional polymers for biomedical applications. In this Minireview, we summarize the most recent examples regarding the design, fabrication, and biomedical applications of CB[n]-based supramolecular polymers (CSPs), which are categorized as noncovalent and covalent CSPs according to the interactions between the CB[n] and polymer backbones. The design principles of CSPs and their unique advantages for biomedical applications, as well as the developmental trends and future perspectives of this cross-disciplinary area are also discussed.