Villarreal Born in
Novelda,
Alicante,
Valencian Community, Mario Gaspar finished his development at
Villarreal CF after arriving from
Albacete Balompié. On 15 March 2009, aged just 18, he made his first-team – and
La Liga – debut, in a game against
Atlético Madrid: he
replaced Giuseppe Rossi with roughly 25 minutes to play, with the score at 2–1, but the
Yellow Submarine eventually lost 3–2 away. Mario Gaspar spent the entire
2009–10 season with
the reserves. He started in all 31 games he appeared in, as they easily retained their newly-found
Segunda División status. Midway through
the following campaign, Mario Gaspar was definitely promoted to the main squad following
Ángel López's severe
knee injury, also making the starting XI. On 16 January 2011, in his first start, he played the full 90 minutes in a 4–2 home win over
CA Osasuna, finishing with 22 appearances. He scored his first competitive goal on 1 May 2012, opening the 3–2 victory at
Sporting de Gijón towards the end of a
season which finished with relegation. In May 2014, with a year remaining on his contract, it was extended for a further four. Mario Gaspar scored his first goal in
European competition on 21 August 2014, concluding a 3–0 away defeat of
FC Astana in the first leg of their
UEFA Europa League play-off (7–0 aggregate). In January 2017, he signed a new deal to last until 2023. On 18 March 2018, Mario Gaspar played his 300th official match for Villarreal, in a 2–1 win at Atlético; only
Cani,
Marcos Senna and teammate
Bruno Soriano had reached that figure before for the club. He filled in as
captain during the lengthy injuries of the last of those players, and on 21 April 2021 with a 2–1 away loss to
Deportivo Alavés he joined him at 400 matches. In
2021–22, still under manager
Unai Emery, Mario Gaspar was kept out of the team by both
Serge Aurier and
Juan Foyth.
Watford On 29 July 2022, Mario Gaspar signed for
EFL Championship club
Watford. He made his league debut on 8 August, a 77th-minute substitute for
Hassane Kamara in the 1–1 draw at
West Bromwich Albion. Mario Gaspar was released in July 2023, having reached an agreement to cancel his contract.
Elche On 31 July 2023, Mario Gaspar returned to Spain, joining second-tier
Elche CF on a one-year contract with an option for a further year. ==International career==