Enveloped RNA viruses have been causative agents of major pandemic outbreaks in the recent past. Glycans present on these virus surface proteins are critical for multiple processes during the viral infection cycle. Presence of glycans serves as a key determinant of immunogenicity, but intrinsic heterogeneity, dynamics, and evolutionary shifting of glycans in heavily glycosylated enveloped viruses confounds typical structure–function analysis. Glycosylation sites are also conserved across different viral families, which further emphasizes their functional significance. In this review, we summarize findings regarding structure–function correlation of glycans on enveloped RNA virus proteins.