Alejo Gastón Montero (born 5 May 1998) is an Argentine professional footballer who plays as a midfielder for Newell's Old Boys.
[3] Gabriel Heinze promoted the midfielder into the club's senior squad during 2018–19, initially selecting him as an unused substitute for a fixture with River Plate on 3 February 2019.
[2] A 1–1 draw with Huracán on 8 February saw Montero make his professional debut, coming off the bench in stoppage time in place of Leandro Fernández.
[2][4] In July 2019, Montero left Vélez to join Primera B Nacional's Agropecuario on a free transfer.
[2] On 25 January 2025, Montero returned to the Argentine Primera División, joining Newell's Old Boys on a three-year contract.