Abstract: Zwitterionic polymers contain equal numbers of cationic and anionic groups along their molecular chains and are overall electrically neutral. This unique chemical architecture endows them with a series of remarkable properties, including strong hydration capacity, anti-polyelectrolyte behavior, favorable biocompatibility, and high ionic conductivity. Benefiting from these advantageous characteristics, zwitterionic polymers have garnered widespread attention and undergone rapid development in diverse fields such as antifouling, membrane separation, drug delivery, and energy. In this review, zwitterionic polymers are first classified and described according to their chemical structures, followed by a systematic summary and discussion of their promising emerging applications in various fields. Finally, the key challenges remaining in current research are summarized, and an outlook on potential future directions is provided, aiming to offer valuable reference and guidance for subsequent investigations.