The 2020 Portuguese Social Democratic Party leadership election was held on 11 and 18 January 2020. As no candidate received a majority of all valid votes on the first round, held on 11 January 2020, a second round took place one week later, 18 January, between the two candidates with the highest number of votes in the first round. This was the first time that a Social Democratic Party leadership election was contested on a second ballot.

The Social Democratic Party is a liberal-conservative political party in Portugal that is currently the country's ruling party. Commonly known by its colloquial initials PSD, on ballot papers its initials appear as its official form PPD/PSD, with the first three letters coming from the party's original name, the Democratic People's Party. A party of the centre-right, the PSD is one of the two major parties in Portuguese politics, its rival being the Socialist Party (PS) on the centre-left.