N3-Ethyl pseudouridine is an N3-ethyl-substituted pseudouridine derivative belonging to the C-nucleoside and N-alkylated nucleoside classes. The pseudouridine scaffold is a C-glycosyl pyrimidine in which a β-D-ribofuranosyl residue is linked to the pyrimidine base through a C–C glycosidic bond. In N3-Ethyl pseudouridine, an ethyl substituent is introduced at the N3 position, and the compound can be used in research on modified nucleosides and pseudouridine derivatives.