2017 Chilean general election

General elections were held in Chile on 19 November 2017 to elect the president, all 155 members of the Chamber of Deputies, 23 of the 43 members of the Senate and 278 members of regional boards. All elected members would serve a four-year term, aside from the senators would serve for eight years.

In the presidential election, former president Sebastián Piñera received a lower-than-expected 36% of the vote, nearly 14 points ahead of senator Alejandro Guillier, who was backed by the sitting administration. In the runoff election on 17 December 2017, Piñera surprised many by defeating Guillier with 54% of the vote, and turnout was two points higher than in the first round.

In the parliamentary elections, the Chile Vamos coalition, which supported Piñera's candidacy, won 46% of the Chamber of Deputies and 44% of the Senate, while the governing New Majority alliance, which competed without the Christian Democrats for the first time in 28 years, failed to retain its majority in both chambers, receiving just 28% and 35% in the lower and upper chambers, respectively. The leftist bloc Broad Front elected 20 deputies (13%) and gained one senator. The Christian Democratic Party received 9% of the lower chamber and secured 14% of the Senate.

Following an election reform in 2015, the Chamber of Deputies grew in size to 155 members from the previous 120, while the Senate increased its membership from 38 to 43 after this election, and will grow to 50 following the election in 2021. Multi-seat constituencies were reestablished, replacing the previous binomial system of two seats per district, installed by the outgoing Pinochet dictatorship in 1989. Starting with this election, Chile's congress was elected through open list proportional representation under the D'Hondt method. Also for the first time, a 40% gender quota was put in place for candidates of each political party in parliamentary elections.

All the newly elected officials began their terms on 11 March 2018.

This was the first non-primary election in which Chilean citizens voted from abroad.

According to the Constitution, primaries are voluntary but its results are binding. Sebastián Piñera won the Chile Vamos primary with 58% of the vote while Beatriz Sánchez became the Broad Front (Frente Amplio) nominee with nearly 68%.

These candidates officially registered their candidacies before the national election authority (Servel), either directly, or via a primary election victory. All candidacies were accepted (met legal requirements) by the Servel on September 1, 2017 and were officially registered on September 12, 2017, after no legal challenges were raised.