AbstractFmoc‐protected β3hserine (β3hSer) was prepared andO‐linked to suitably protectedN‐acetylgalactosamine (GalNAc) andN‐acetylglucosamine (GlcNAc) derivatives. Glycosylation of β3hSer was made by two independent routes: either by direct glycosyl linkage to the β3hSer, or linkage to naturalL‐Ser and then utilizing the carbohydrate moiety as a protecting group in an Arndt–Eistert homologation. Both procedures gave the novel glycosylated β3‐amino acids Fmoc‐β3hSer(α‐D‐GalNAc(Ac)3)‐OH (1a), its β‐anomer (1b), and Fmoc‐β3hSer(β‐D‐GlcNAc(Ac)3)‐OH (2), which were utilized in the solid‐phase peptide synthesis of four glycosylated dipeptides (3a–d) and two heptapeptides (4a–b). The preparation of β‐amino acids bearing common post‐translational modifiers represents an important step towards functionalized foldamers with broad applications in biomedical research. Copyright © 2