Platelet glycosylation is essential for platelet production, function, and clearance. This chapter focuses on how glycan capping structures, particularly sialic acid and galactose, influence thrombopoiesis, receptor activity, and platelet lifespan. It outlines the roles of N-linked glycoprotein glycans, O-linked glycoprotein glycans, and glycosaminoglycans in platelet homeostasis and highlights congenital disorders of glycosylation involving genes that regulate N-glycosylation, sialic acid and galactose capping, and glycosphingolipid synthesis, each contributing to platelet dysfunction and altered circulating platelet counts. Advances in glycomics, proteomics, and glycoinformatics are also described which now enable detailed investigation of platelet glycans, offering insight into disease mechanisms. Highlighted is the emerging recognition of glycobiology as a key determinant of platelet homeostasis in health and disease.