Stimulus-responsive polymer brushes (SRPBs) exhibit a change in conformation and structure, often accompanied by a noticeable change in surface energy, due to an external stimulus such as a change in solvent composition, temperature, pH, ionic strength, light, or mechanical stress. SRPBs offer exciting andnewpossibilities to fabricate adaptive or responsive smart materials. This review summarizes selected, recent progress in SRPB applications in the field of surface wettability switching, mechanical actuation, and environmental sensing. Furthermore,wereview selected papers from an emerging area in which SRPBs are used for nano- and microfabrication.