Fung, AlfredCoote, Michelle2022-10-070959-8103http://hdl.handle.net/1885/274364Since its invention 25 years ago, atom transfer radical polymerization has become one of the most dominant methods in controlled radical polymerization. This rise in importance is due in large part to increases in scope, reduced catalyst loading and improved oxygen tolerance. These developments have been in turn underpinned by an improved understanding of the mechanism, kinetics and structure-reactivity trends. This mini‐review outlines these mechanistic developments with a particular emphasis on the relationship between structure and activity in both the catalyst and alkyl halide substrate, and their implications for future catalyst design.MLC gratefully acknowledges an Australian Research Council Lau-reate Fellowship (FL170100041).application/pdfen-AU© 2020 Society of Industrial Chemistry202110.1002/pi.61302021-11-28