We report on the design of glycosylated nanogels via core-cross-linking of amphiphilic non-water-soluble block copolymers composed of an acetylated glycosylated block and a pentafluorophenyl (PFP) activated ester block prepared by reversible addition-fragmentation (RAFT) polymerization. Self-assembly, pH-sensitive core-cross-linking, and removal of remaining PFP esters and protecting groups are achieved in one pot and yield fully hydrated sub-100 nm nanogels. Using cell subsets that exhibit high and low expression of the mannose receptor (MR) under conditions that suppress active endocytosis, we show that mannosylated but not galactosylated nanogels can efficiently target the MR that is expressed on the cell surface of primary dendritic cells (DCs). These nanogels hold promise for immunological applications involving DCs and macrophage subsets.