General elections were held in Costa Rica in 2018 to elect both the President and Legislative Assembly. The first round of the presidential election was held on 4 February 2018, with the two highest-ranked candidates being Christian singer and Congressman Fabricio Alvarado Muñoz from the conservative National Restoration Party and writer and former Minister Carlos Alvarado Quesada from the progressive Citizens' Action Party, gaining 24% and 21% of the votes respectively. As no candidate received more than 40% of the first round vote, a second round run-off election was held on 1 April 2018 and was won by Carlos Alvarado Quesada, with a landslide victory of 60.6% of the vote.

The previously dominant National Liberation Party suffered its worst results to date, ending third in the presidential run for the first time in its history with its candidate former Legislative Assembly President Antonio Álvarez Desanti winning only 18%. Other notable candidates were lawyer and entrepreneur Rodolfo Piza from the center-right Social Christian Unity Party with 16% and right-wing populist Juan Diego Castro with 9%.

In the 57-seat Legislative Assembly, the National Liberation Party won 17 seats, the National Restoration Party won 14 seats (although their parliamentary group later split in half due to factionalism), the Citizens' Action Party won 10 seats, the Social Christian Unity Party won 9 seats, the National Integration Party won 4 seats, the Social Christian Republican Party (an offshoot of PUSC) won 2 seats and left-wing Broad Front won 1 seat.

The President of Costa Rica is elected using a modified two-round system in which a candidate must receive at least 40% of the vote to win in the first round; if no candidate wins in the first round, a runoff will be held between the two candidates with the biggest quantity of votes.

The 57 members of the Legislative Assembly are elected using closed list proportional representation through the largest remainder method from seven multi-member constituencies with between four and 19 seats, which are based on the seven provinces. Party lists were required to alternate between male and female candidates, with parties also required to have three or four of their seven regional lists headed by a female candidate.

The internal elections for the Citizens' Action Party were held on 9 July 2017. The candidates were two former ministers of the Solís Rivera administration; writer Carlos Alvarado, former Minister of Labour and Social Issues, and economist Welmer Ramos, former Economy Minister. Alvarado won by 56% of the votes. Deputies Epsy Campbell, Ottón Solís and Vicepresident Ana Helena Chacón declined a potential run.

Carlos Alvarado was the first one of the party to announce his intention to run under the slogan of "I choose the future" (Elijo el futuro) and ran under a progressive platform, which sought to exalt the achievements of Luis Guillermo Solis's government and promised to continue with it. Meanwhile, Welmer Ramos's campaign focused more on a moderate and conservative campaign, under the slogan "A citizen like you" (Un ciudadano como usted) and openly criticized the then government to appeal to those who were upset with the administration.

The Libertarian Movement had its first primaries on 30 June 2017.