Parliamentary elections were held in Colombia on 11 March 2018 to elect 102 members of the Senate and 165 members of the House of Representatives.

The Chamber of Representatives consisted of 172 members; 162 were elected by proportional representation from 33 multi-member constituencies based on the departments, with seats allocated using the largest remainder method.

[2] Although a new constituency had been created for the Raizal minority, legislation had not been approved to allow the election to take place.

A further five seats were reserved for FARC and one for the running mate of the runner-up in the presidential election as part of the Colombian peace process.

[3][4] The Senate consisted of 108 members; 100 were elected a single nationwide constituency by proportional representation (with seats allocated using the largest remainder); two were elected from a two-seat constituency for indigenous Colombians;[5] five were reserved for FARC and one for the runner-up in the presidential election.