Costa Rica participated at the 2018 Summer Youth Olympics in Buenos Aires, Argentina from 6 to 18 October 2018.

Costa Rica qualified a boys' based on their performance at the 2018 AFECAVOL Zone U19 Championship.

[1] Costa Rica was given a quota to compete by the tripartite committee.

[2] Costa Rica qualified one gymnast based on its performance at the 2018 American Junior Championship.

[3] Costa Rica qualified 2 athletes (1 boy and 1 girl) to compete in swimming.