39th Federal Congress of the PSOE

The 39th Federal Congress of the Spanish Socialist Workers' Party was held in Madrid between 16 and 18 June 2017, to elect a new party leadership in the Spanish Socialist Workers' Party (PSOE) and set out the party's main lines of action and strategy, after the sacking of Pedro Sánchez as party leader in October 2016 had resulted in a caretaker leadership being appointed. The primary election was held on 21 May 2017, after being confirmed in a federal committee on 1 April.

The leadership race was the first to be held after the party's electoral setbacks in both the 2015 and 2016 general elections in which the party scored its two worst electoral records since the Spanish transition to democracy. An extraordinary party congress had been held in July 2014 after Alfredo Pérez Rubalcaba's resignation, in which Pedro Sánchez had been elected as new party leader. However, no ordinary congress had been held since 2012. Former President of the Congress of Deputies and former Lehendakari Patxi López publicly announced his bid as candidate on 15 January, with President of the Regional Government of Andalusia Susana Díaz and Sánchez himself following suit.

The election resulted in Pedro Sánchez being re-elected as Secretary General in a landslide. Sánchez would ultimately lead the PSOE into government after a successful vote of no confidence which would see Prime Minister Mariano Rajoy and his People's Party ousted from power.