Sugar linkers are bioconjugation linkers containing carbohydrate moieties that connect payloads to targeting molecules, enhancing drug delivery, stability, and specificity. Variants include β-glucuronide linkers, which release drugs upon enzymatic cleavage by β-glucuronidase; sugar-PEG linkers, which improve solubility and biocompatibility; and GalNAc linkers, which target the liver via ASGPR binding. Sugar linkers enable controlled drug release, targeted delivery to carbohydrate receptor-expressing cells, and improved pharmacokinetics in applications such as antibody-drug conjugates, imaging probes, and surface modifications. Their hydrophilicity reduces aggregation and enhances circulation stability, making them valuable in therapeutics, diagnostics, and biochemical research, including enzyme assays and carbohydrate-protein interaction studies.