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. For both ballots, more than 40,000 party members, just 36 percent out of almost 110,000 active members, were registered to vote.[1]
In the first round of the election, incumbent party leader Rui Rio finished in first place with a relative majority of 49.0% of all valid votes cast, followed by contesters Luís Montenegro, who received 41.4% of the vote, and Miguel Pinto Luz, who won 9.6% of the vote.[2] As no candidate managed to reach the required percentage of the vote to win outright in the first round, a run-off election took place between the two candidates with the most votes in the first round: Rio and Montenegro. Rui Rio won the second round with 53.2% of the vote and was thus re-elected President of the party and stayed on as Leader of the Opposition.[3]