Nicolás Mejía (Spanish pronunciation: [nikoˈlas meˈxi.a];[a] born 11 February 2000) is a Colombian tennis player.

Mejía received wildcards for the qualifying competition at the 2024 Los Cabos Open and also for the 2024 Abierto Mexicano Telcel in Acapulco.

After coming through qualifying, Mejía won his first Challenger singles title in the 2024 San Luis Open Challenger in San Luis Potosí, Mexico, defeating fellow qualifier Matías Soto in the final.

Following a final showing at the 2024 Morelos Open also as a qualifier, defeating third seed Zachary Svajda, Dominik Palán, wildcard Vasek Pospisil[3] and sixth seed Maxime Cressy, he returned to the top 300 on 15 April 2024.

235, Mejía entered the main draw of the 2024 Winston-Salem Open as a lucky loser but lost to Corentin Moutet.