[1] Since Portugal ascended from seventh to sixth place in the UEFA association coefficient rankings at the end of 2019–20 season, the three best-ranked teams could qualify for the UEFA Champions League (the champions and runners-up entered directly into the group stage, and the third placed team entered the third qualifying round).

[2] Due to the COVID-19 pandemic in Portugal, since March 2020, in contrast with various European leagues, the Primeira Liga began playing matches behind closed doors.

On 13 September, Sporting confirmed that three players had tested positive for coronavirus, leading their pre-season match against Napoli to be cancelled due to the orders of the Portuguese Ministry of Health.

[4] Meanwhile, Gil Vicente confirmed that fifteen players had tested positive for coronavirus, leading also their pre-season match against Vitória de Guimarães to be cancelled.

Nacional and Farense were promoted on 5 May 2020 by decision of the Liga Portuguesa de Futebol Profissional, after the suspension of the 2019–20 LigaPro due to the COVID-19 pandemic in Portugal.

This decision was made based on UEFA's recommendations, focusing on sporting merit, as these teams were in first and second place of the LigaPro, respectively, at the time of cancellation.

They replaced Desportivo das Aves and Vitória de Setúbal, who were relegated after three and sixteen seasons in the top flight, respectively.