Marcos Alonso (footballer, born 1990)

Marcos Alonso
Alonso with Chelsea in 2017
Personal information
Full name Marcos Alonso Mendoza
Date of birth (1990-12-28) 28 December 1990
Place of birth Madrid, Spain
Height 1.88 m (6 ft 2 in)
Position(s) Defender
Team information
Current team
Celta
Number 20
Youth career
Alcobendas
Unión Adarve
2002–2008 Real Madrid
Senior career*
Years Team Apps (Gls)
2008–2010 Real Madrid B 39 (3)
2010 Real Madrid 1 (0)
2010–2013 Bolton Wanderers 35 (5)
2013–2016 Fiorentina 58 (4)
2014Sunderland (loan) 16 (0)
2016–2022 Chelsea 154 (25)
2022–2024 Barcelona 29 (1)
2024– Celta 31 (3)
International career
2009 Spain U19 3 (0)
2018–2022 Spain 9 (0)
Medal record
Men's football
Representing  Spain
UEFA Nations League
Runner-up2021 Italy
*Club domestic league appearances and goals, correct as of 00:21, 27 May 2025 (UTC)

Marcos Alonso Mendoza (born 28 December 1990) is a Spanish professional footballer who plays either as a left-back or centre-back for La Liga club Celta de Vigo.

He started his career at Real Madrid but went on to make his name with Bolton Wanderers in England and later with Fiorentina in Italy. His success at the latter club led Chelsea to sign him for an estimated £24 million in 2016, going on to win multiple honours including the Premier League in the 2016–17 season and the UEFA Champions League in 2021.

Alonso made his full debut for Spain in March 2018. He went on to earn nine caps in four years.