Dispersion polymerization of n‐butyl acrylate has been performed in a mixture of ethanol and water in the presence of poly(N‐acryloylmorpholine) (polyNAM). These hydrophilic polymer chains are synthesized by the RAFT process and thus incorporate well‐defined chain ends. The dithioester ω‐end group is used as an efficient chain transfer agent under dispersion polymerization conditions to produce hairy poly(n‐butyl acrylate) latex particles. Moreover, pre‐functionalization of the polyNAM chains on the α‐end by a carbohydrate derivative is also achieved to obtain directly functionalized particles according to the same strategy.