Hugo Guillamón Sanmartín (born 31 January 2000) is a Spanish professional footballer who plays as a central defender or midfielder for La Liga club Valencia and the Spain national team.

[3] He made his senior debut with the reserves on 16 December 2017, coming on as a first-half substitute for Ivan Zotko in a 0–0 Segunda División B home draw against CF Badalona.

[5] Guillamón made his first team – and La Liga – debut on 22 February 2020, replacing injured Eliaquim Mangala at half-time in a 3–0 defeat away to Real Sociedad.

After consulting the video assistant referee, his third-minute dismissal was the earliest on a La Liga opening weekend; his team nonetheless won 1–0.

[13] Due to the isolation of some national team players following the positive COVID-19 test of Sergio Busquets, Spain's under-21 squad were called up for the international friendly against Lithuania on 8 June 2021.