Ion channels play a crucial role in cell functioning, contributing to transmembrane potential and participating in cell signalling and homeostasis. To fulfil highly specialised functions, cells have developed various mechanisms to regulate channel expression and activity at particular subcellular loci, and alteration of ion channel regulation can lead to serious disorders. Glycosylation, one of the most common forms of co- and post-translational protein modification, is rapidly emerging as a fundamental mechanism not only controlling the proper folding of nascent channels but also their subcellular localisation, gating and function. Moreover, studies on various channel subtypes have revealed that glycosylation represents an important determinant by which other signalling pathways modulate channel activity. The discovery of detailed mechanisms of regulation of ion channels by glycosylation provides new insights in the physiology of ion channels and may allow developing new pharmaceutics for the treatment of ion channel-related disorders.