Organoselenium chemistry has become an important tool in synthetic and medicinal chemistry. Organoselenium reagents are more commonly known as electrophiles, but there are a few organic transformations where they act as nucleophiles. These reagents have been successfully employed to achieve a number of synthetically important transformations, such as oxyselenenylations, selenocyclisations, and selenoxide eliminations. In past two decades, another episode of their success was introduced with the development of potential catalysts in organic synthesis. Various selenium-catalysed transformations, such as oxidation, reduction, cyclisation, rearrangement and stereoselective reactions have been successfully investigated. To conduct these reactions, a number of organic and inorganic oxidants were employed to regenerate different active catalytic species in situ. In this review article, recently developed selenium-catalysed reactions are covered including stereoselective reactions.