Senate of Chile

According to Article 190 of the Constitution, the Senate is composed of fifty directly elected senators, chosen by universal suffrage in 16 senatorial constituencies, which correspond to Chile's regions (the more populous regions elect more than two senators). Seats within each constituency are allocated using the D'Hondt method of proportional representation. Senators serve eight-year terms, with half of the chamber renewed every four years: constituencies with odd numbers (I, II, IV, VI, IX, XI and XIV) are renewed in one election cycle, and those with even numbers, together with the Santiago Metropolitan Region (III, V, VII, VIII, X, XII, XIII, XV and XVI), in the next.

Requirements

To be elected, a candidate must be a citizen entitled to vote, must have completed secondary education or its equivalent, and must be at least 35 years old; before a 2005 reform the minimum age was 40. Party candidates must have been affiliated with their party for at least two months before the close of candidate registration and must not have belonged to another party in the preceding nine months; independent candidates must not have belonged to any party in the nine months before registration closes and must gather the number of citizen signatures required by the Electoral Service (Servel), unless running as part of an electoral list. If a seat becomes vacant through death, incapacity or disqualification, the vacancy is filled by a nominee of the party the senator belonged to at the time of election; if the seat was held by an independent, it is left vacant for the remainder of the term.

Besides its ordinary role in the legislative process alongside the Chamber of Deputies and the President of the Republic, Article 53 of the Constitution grants the Senate a number of exclusive powers, including the authority to:

• Hear constitutional accusations (impeachments) brought by the Chamber of Deputies.
• Decide whether legal proceedings may be brought against a minister of state for acts performed in office that are alleged to have caused unjust harm.
• Resolve jurisdictional disputes between political or administrative authorities and the higher courts of justice.
• Restore Chilean nationality to persons who have lost it.
• Grant or withhold consent for acts of the President of the Republic in cases where the Constitution or the law so requires.
• Authorize the President of the Republic to leave the country for more than thirty days, or during the final ninety days of his or her term.
• Declare, after hearing the Constitutional Court, the incapacity of the President of the Republic, and rule on the President's resignation.
• Approve appointments proposed by the President of the Republic where the Constitution or the law requires Senate consent, such as the appointment of Supreme Court justices or members of the Central Bank of Chile's board.

Standing committees

Legislative bills and other matters referred to the Senate are studied in detail by permanent committees, each composed of a set number of senators.

Senators receive a monthly parliamentary allowance (dieta parlamentaria) which, under Article 62 of the Constitution, is equivalent to the salary of a minister of state. As of 2026 the gross monthly dieta is approximately CLP$7,348,983, a figure unchanged since December 2023, before legally mandated deductions such as taxes and pension contributions. In addition to the dieta, senators receive parliamentary allowances intended solely for the exercise of their legislative duties, administered under the supervision of the Resolutive Council of Parliamentary Allowances (Consejo Resolutivo de Asignaciones Parlamentarias); these funds are not personal remuneration but cover support staff, external advice, operating expenses, district offices, transportation and outreach activities. For 2025, total monthly allowances per senator amounted to roughly CLP$23,281,823, with the exact figure varying by constituency and additional allowances for fuel and travel to the district. The size of the dieta has been the subject of public debate and repeated reform proposals, including bills to change how it is set and to suspend its payment in cases where a senator's parliamentary immunity is lifted.

The Senate of Chile was created in 1812 to support the policymaking of the Government Junta. It has since undergone several constitutional reorganizations that have altered its powers, composition, and method of selection.

First Senate (1812-1814)

The first Senate was created by Article 7 of the Provisional Constitutional Manual of 1812, promulgated on 27 October 1812. It was composed of seven members, one of whom served as president on a rotating four-month basis, plus a secretary; three alternate members were also named. Members, called diputados rather than senators, were chosen through public subscription, with three from Santiago, two from the Province of Coquimbo, and two from the Province of Valparaíso. The body was inaugurated on 10 November 1812 under its first president, Pedro Vivar y Azúa, and was intended to counterbalance the executive power of the Government Junta; the government could not decide matters affecting the security of the Patria without its assent. During its existence it approved a freedom-of-the-press law and helped create the Instituto Nacional and Chile's first National Library. It functioned until January 1814, when it was reorganized amid successive military defeats in the Chilean War of Independence.

Consultative Senate (1814)

A revised body, the Consultative Senate, was created by Article 13 of the Provisional Government Manual of 17 March 1814. Like its predecessor it had seven members, this time formally titled "senators" and without alternates, elected for two-year terms. Members were selected by the Supreme Director from a list of 21 candidates nominated by the provinces, and its legislative powers were curtailed, transforming it into a consultative body similar to a council of state. It functioned only until the disaster of Rancagua on 1-2 October 1814 ushered in the Spanish Reconquista, during which no Senate or Congress existed in Chile until 1817.

First conservative senate (1818-1822)

Created by Title III of the Constitution of 1818 under Bernardo O'Higgins, this Senate was composed of five titular and five alternate members, all designated directly by the Supreme Director, for a total of ten. It was meant to function only when the lower house was not in session, issuing "provisory rules" with the same force as law, hence the "conservative" label, since it "conserved" legislative power in the interim before an elected Congress could be convened. The body played a role in seeking international recognition of Chilean independence, including at a diplomatic convention in Aix-la-Chapelle (Aachen), but drew growing criticism for retaining an appointed, non-Congressional structure. It functioned from October 1818 to May 1822.

Fourth Senate and the Constitution of 1823

The Senado Conservador y Legislador of 1823, established under the Constitution of 1823, was the second Senate since 1812 to be composed of popularly elected members. It comprised nine senators elected from a single national constituency for six-year terms, with unlimited re-election; candidates had to be at least 30 years old, own property worth at least 5,000 pesos, have resided in the country for the preceding three years, and be eligible to vote. This Senate held a near-monopoly on legislative power in an asymmetrical parliament in which the lower National Chamber had little influence over lawmaking; the Senate also ratified international treaties and tax legislation, and, notably, could suspend the Supreme Director from office, the first institutional check on the executive. Political instability interrupted its work, and it was dissolved for good in 1824, replaced by the unicameral Congreso General de la Nación.

Constitutions of 1828 and 1833

Only from 1828 onward was the Senate conceived as a chamber of a bicameral Congress. Under the Constitution of 1828, the Senate was composed of two representatives chosen by each of the country's provincial assemblies (16 senators in total) for four-year terms, giving it a close link to regional governments; it possessed few exclusive powers beyond ruling on impeachments passed by the Chamber of Deputies, leaving the lower house with greater legislative and political weight.

The Constitution of 1833 instead created a 20-member Senate elected from a single national list through an indirect system of electors, for nine-year terms with unlimited re-election. An 1874 reform introduced direct election by province, apportioning one senator per three deputies (plus any fraction of two) from each province, and shortened the term to six years, still indefinitely renewable. Under the Constitution of 1925, the Senate came to be elected directly from nine (from 1925) and later ten (from 1967) provincial groupings, for eight-year terms renewable without limit, with half of the chamber replaced every four years.

Original design of the 1980 Constitution

Under the military-era Constitution of 1980 as originally enacted, the Senate combined popularly elected members with unelected ones. Alongside senators chosen by the people (two per region, 26 in total), the chamber included nine designated senators and senators for life. The designated senators, renewed every eight years and not replaced if a seat fell vacant before the end of that period, were nominated as follows: four by the National Security Council from among former commanders-in-chief of the armed forces or a former director general of the Carabineros; three by the Supreme Court (two of whom had to have served at least two consecutive years as justices of that court, and one who had served an equivalent period as Comptroller General); and two by the President of the Republic (one a former university rector, the other a former cabinet minister). Former presidents who had completed a full constitutional term became senators for life by right. Two former heads of state, Eduardo Frei Ruiz-Tagle and Augusto Pinochet, were installed as lifetime senators.

1990 to 2017

Chile originally had thirteen senatorial constituencies, one per region, but constitutional reforms approved in 1989 allowed the six most populous regions to be split into two constituencies each, raising the number of directly elected senators from 26 to 38 while retaining designated and lifetime senators. Between 1990 and 2006 the Senate accordingly ranged between 47 and 49 members in total. Although some designated senators carried genuine institutional weight, the arrangement was seen as a check on elected majorities, and governments after 1990 often had to negotiate with this "institutional" bloc to secure legislative majorities. Only Eduardo Frei Ruiz-Tagle (2000-2006) served as a lifetime senator on the basis of a completed presidential term; Augusto Pinochet held the same status by right from 1998 to 2002, resigning it before his death.

A constitutional reform promoted under the government of Ricardo Lagos and approved nearly unanimously by Congress eliminated designated and lifetime senators effective 11 March 2006, reducing the Senate to 38 fully elected members, all chosen for eight-year terms from 19 constituencies electing two senators each. Frei lost his lifetime seat in the reform but remained in the Senate after winning an elected one.

2017 to the present

A 2015 constitutional reform, enacted under the second government of Michelle Bachelet, replaced the binomial electoral system and set the Senate's current size at 50 members elected from 16 constituencies. Twenty-three senators for the odd-numbered constituencies (I, II, IV, VI, IX, XI and XIV) were elected in 2017, and the remaining 27 senators, for constituencies III, V, VII, VIII, X, XII, XIII, XV and XVI, in 2021, completing the transition to the new system.

The Senate's continued existence was debated by the Constitutional Convention, which drafted a proposed new constitution between 2021 and 2022; the draft would have abolished the Senate and replaced it with a "Chamber of the Regions" with different powers. Voters rejected the proposed constitution in the 4 September 2022 plebiscite, and the Senate's abolition did not proceed.

The Senate elected in the 16 November 2025 general election (which renewed the seven odd-numbered constituencies) took office on 11 March 2026, alongside the 57th National Congress and the government of President José Antonio Kast. Senator Paulina Núñez of National Renewal was elected the chamber's president that day, with Iván Moreira (UDI) as vice-president, under a four-year power-sharing agreement among the parties of the governing coalition and Democratic Socialism under which the presidency is due to rotate to the Socialist Party, the UDI and Evópoli in successive years.

According to polling by Adimark, the Senate's approval rating never exceeded 50 percent during the first government of President Sebastián Piñera (2010-2014), and generally trended downward, reaching lows of 17 percent in April, July and August 2012 and again in August and September 2013; disapproval peaked at 77 percent in August 2012. The April 2012 decline coincided with senators' approval of an increase of two million pesos in their own allowances.

The Senate is currently composed of 50 members. Senators organize themselves into parliamentary committees (comités), generally along party lines, which are distinct from the broader government/opposition blocs shown in the infobox above.

Parliamentary committees (as of 2026)

List of senators by constituency

The table below reflects the Senate's official roster as of September 2026, including the senators elected on 16 November 2025 for constituencies I, II, IV, VI, IX, XI and XIV, who took office on 11 March 2026 for terms expiring in 2034.