As no presidential candidate won a majority in the first round, a runoff was held on 19 November, in which Javier Milei defeated Sergio Massa to become President of Argentina.

In the 2019 general election, the Peronist, left-wing Frente de Todos ticket of Alberto Fernández, former Cabinet Chief, and Cristina Fernández de Kirchner, National Senator and former president, defeated the center-right Juntos por el Cambio ticket of incumbent president Mauricio Macri and conservative Peronist National Senator Miguel Ángel Pichetto, exceeding the threshold to win the presidency in a single round.

[14] The first two years of the Fernández presidency were limited by the COVID-19 pandemic in Argentina, during which he imposed strict lockdown measures in an attempt to suppress the spread of the disease,[15] and a debt crisis.

"[23] The 2021 midterm elections resulted in heavy losses for the Frente de Todos, which lost its majority in both houses of Congress.

[29][30] The 2023 election was held amid a severe economic crisis with over 140% inflation and 40% poverty which observers said would negatively affect the ruling party's chance for another term.

[40][41] The 257 members of the Chamber of Deputies are elected by proportional representation in 24 multi-member constituencies based on the provinces (plus the City of Buenos Aires).

[70] Massa conceded and announced his retirement from politics after the runoff election results showed that he had lost by roughly 11 percentage points.

[71] Incumbent and retiring president Alberto Fernández congratulated Milei: "I am a man of democracy, and I value nothing more than the popular verdict.

"[72] Bolivia: Bolivian president Luis Arce wished success to Javier Milei and said that he would work hard to keep "firm relations" with Argentina.

On the other hand, former president Evo Morales said that he would never wish success to "[Milei's] fascism, far-right and neoliberalism, who supports the Zionist genocide and Yankee imperialism.

"[73][74] Brazil: Brazilian president Luiz Inácio Lula da Silva congratulated Milei without mentioning his name, saying: "Democracy is the voice of the people, and it must always be respected.

At the IDB, we are ready to continue our collaboration with the country and promote sustainable and inclusive economic development for the benefit of its citizens.

"[77] Mexico: Mexican president Andrés Manuel López Obrador called Argentina's election of Milei an "own goal".

Wishing him the greatest success in his administration, Peru renews its commitment to continue strengthening the historic ties of friendship and cooperation that unite our countries.

"[72] Russia: Russian president Vladimir Putin congratulated Milei, despite the latter support for Ukraine in the Russo-Ukrainian War.

We look forward to working with President-elect Milei and his government on shared priorities that benefit the people of both countries, including protecting human rights and democracy, addressing climate change, and investing in the middle class.

We look forward to building on our strong bilateral relationship based on our shared commitment to human rights, democratic values, and transparency.

"[72] Venezuela: Venezuelan president Nicolás Maduro, reacting to the election results, declared that "the neo-Nazi extreme right won in Argentina, we call for reflection on the emergence of extreme right centers that seek to impose themselves to recolonize Latin America and impose extremist models".