Exon Gustavo Vallecilla Godoy (born 28 May 1999) is an Ecuadorian professional footballer who plays as a centre-back.

Aucas had bought 50% of Vallecilla's rights for $80,000, and that he would join the club permanently from the 2019 season, with Cuenca still holding a sell-on percentage.

[10] On 5 April 2021, Vallecilla joined Major League Soccer club FC Cincinnati on loan for the 2021 season with an option to buy.

[14] On 1 December 2021 Cincinnati confirmed, that they had triggered the buying option in Vallecilla's contract, adding him to the squad for the 2022 season.

[15][16] On 28 March 2022, Colorado Rapids announced that they acquired Vallecilla for $800,000 in General Allocation Money with extra performance-based fees.