Selenium (Se) is an important element belonging to the chalcogen family. Electrochemistry is of significant importance in various applications of Se and its compounds, ranging from non-vacuum processed solar cells, direct methanol/polymer electrolyte membrane fuel cells, electrocatalysts, batteries, and metallic alloys. However, rich information on Se electrochemistry remains unexplored in the last few decades. Here we made an attempt to assess the reported studies on electrochemical behaviours of Se. Fundamental concepts of Se electrochemistry in aqueous media and ionic liquids at various electrodes, polarographic and cyclic voltammetric analysis, cathodic and anodic stripping analysis, electrodeposition mechanism and electrocatalysis are discussed. Electrochemical atomic layer epitaxy (ECALE) in engineering Se atomic layers and fabrication of Se nanostructures by electrochemical methods are highlighted. Se electrochemistries in application areas are reviewed. Voltammetric studies of Se electrodeposition on molybdenum (Mo) electrode are presented with a view of its applicability in electrodeposited CuInSe₂/CuIn(Ga)Se₂ (CIS/CIGS) solar cells.