Javier "Javi" Serrano Martínez (born 16 January 2003) is a Spanish professional footballer who plays as a midfielder for La Liga club Atlético Madrid.

[4] During the 2020–21 season, Serrano was part of the Juvenil Atlético squad that came top of their group against Rayo Vallecano and Real Madrid, before being defeated by the latter in the Copa de Campeones.

[6][7][8] During the 2021–22 pre-season, Serrano was selected by Diego Simeone to train with the first team, starting games such as their 2–1 win against VfL Wolfsburg.

[14] On 30 June 2023, Serrano moved abroad for the first time in his career, after agreeing to a one-year loan deal with SK Sturm Graz of the Austrian Football Bundesliga.

[3] After the COVID-19 break, that put on hold most junior international competitions, he became a regular with the Spain under-19 team, earning his first selection in late August 2021.