Lithuania participated in the Eurovision Song Contest 2018 with the song "When We're Old" written by Vytautas Bikus. The song was performed by Ieva Zasimauskaitė. The Lithuanian broadcaster Lithuanian National Radio and Television (LRT) organised the national final "Eurovizijos" dainų konkurso nacionalinė atranka in order to select the Lithuanian entry for the 2018 contest in Lisbon, Portugal. The national final took place over nine weeks and involved 50 competing entries. The results of each show were determined by the combination of votes from a jury panel and a public vote. In the final, six artists and songs remained and "When We're Old" performed by Ieva Zasimauskaitė was selected as the winner.

The Eurovision Song Contest 2018 was the 63rd edition of the Eurovision Song Contest. It took place in Lisbon, Portugal, following the country's victory at the 2017 contest with the song "Amar pelos dois" by Salvador Sobral. Organised by the European Broadcasting Union (EBU) and host broadcaster Rádio e Televisão de Portugal (RTP), the contest was held at the Lisbon Arena, and consisted of two semi-finals on 8 and 10 May, and a final on 12 May 2018. The three live shows were presented by Portuguese television presenters Filomena Cautela, Sílvia Alberto and Catarina Furtado, and Portuguese-American actress Daniela Ruah, marking the first time that the contest was presented by four hosts.