SARS-Cov-2 is an RNA virus responsible for the Covid-19 pandemic which already claimed more than 215,000 lives worldwide as of April 28, 2020. Selenium has a key and complex role in the immune system. It is very clear that selenium deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. We present here how selenium deficiency promotes mutations, replication and virulence of RNA viruses. Selenium might be beneficial via various mechanisms including virus-host cell attachment interaction, restoration of host antioxidant capacity, anti-inflammatory and anti-clotting effects, to name a few. Selenium has been overlooked but probably has a significant place in Covid-19 management, especially in the elderly, and might represent a game changer in the global response to Covid-19.