Tomás Jesús Alarcón Vergara (born 19 January 1999) is a Chilean professional footballer who plays for Colo-Colo and the Chile national team.

Alarcón started to establish himself as a starter for the club midway through the 2018 campaign, where he was also utilised as a central defender by manager Gabriel Milito.

Alarcón made his debut for Chile senior team on 5 September 2019 in a friendly match against Argentina, as a 55th-minute substitute for Claudio Baeza.

[10] He was considered by Martín Lasarte to play in the 2022 FIFA World Cup qualification, having his first official international presentation against Argentina on 3 June 2021.

In the same month, Alarcón was nominated to participate in the 2021 Copa América,[11] playing in four games of the tournament, in which Chile lost at the quarter-finals against Brazil.