Jaime Sierra Mateos (born 18 March 1998) is a Spanish footballer who plays as a central midfielder.
[2] In August 2017, free agent Sierra moved to CD Leganés, being assigned to the reserves in Tercera División.
[3] He made his senior debut late in the month, coming on as a second-half substitute in a 3–2 away win against AD Alcorcón B.
[4] Sierra made his first team – and La Liga – debut on 28 January 2018, replacing José Naranjo in a 3–2 home win against RCD Espanyol.
[7] He left the club in December 2024 after Deinze was declared bankrupt and ceased operations.