Domestically, Benfica lost the Supertaça Cândido de Oliveira match, were eliminated in the semi-finals of the Taça da Liga, finished third in the Primeira Liga – their worst league position since 2008–09 – and lost a Taça de Portugal final for a second time in a row. This season, Benfica invested €105 million amid the COVID-19 pandemic, a record investment in Portuguese football.
The 2020–21 Sport Lisboa e Benfica season was the club's 117th season in existence and its 87th consecutive season in the top flight of Portuguese football.
