The drastic development of polymeric materials for a wide range of biomedical and biomaterial applications has been explored in the last few decades. Among these materials, a new class of ‘smart’ or ‘intelligent’ biomaterial has been developed, and these materials are highly responsive to slight changes in their environments. Due to their dynamically alterable properties, smart materials allow for smart biomaterials to be developed. This review presents smart thermo-responsive polymers and discusses how they may be used as smart biomaterials. We describe typical thermo-responsive polymers that are either lower critical solution temperature-type, upper critical solution temperature-type, or thermo-induced shape-memory polymers. The basic mechanisms of the thermo-response processes will also be described. The applications of smart biomaterials with various forms, such as smart fibres, surfaces and hydrogels, will also be introduced.